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Digitized  by 

the  Internet  Archive 

in  2015 

https://archive.org/details/practicaltreatisOOgill_0 


Professional  Papers  of  the  Corps  of  Ei^gin-eers,  U.S.A. 

No.  9. 


PRACTICAL  TREAT! 


LIMES  HYDEAULIC  CEMENTS, 


MORTARS 


BY 


Q.  A.  GILLMOEE,  A.M., 

Lieutenant-Colonel  U.  S.  Corps  of  Engineers,  Brevet  Major-Geh.  U.  S.  Army. 


EIGHTH  EDITION. 


D.    VAN    NOSTRAND,  PUBLISHER 

33  MuBRAT  Street  and  27  Warren  Street. 


1886. 


TA 


Entered  according  to  Act  of  Congress,  in  the  year  1872, 
BY  D.  VAN  NOSTRAND, 
In  the  Office  of  the  Librarian  of  Congress  at  Washington. 


isroTE. 


The  experiments  and  researches,  wLicli  fumisli  tlie 
groundwork  for  all  tlie  original  matter  contained  in 
tlie  following  work,  were  conducted  under  the  authority 
of  the  Engineer  Bureau  of  the  War  Department,  and 
were  completed  in  the  summer  of  1861.  The  manu- 
script was  nearly  ready  for  the  publisher  at  the  same 
time. 

Since  then,  active  professional  duties  have  rendered 
it  impossible  for  me  to  devote  even  a  brief  personal 
superintendence  to  the  publication  of  the  work.  I  am, 
therefore,  not  insensible  to  the  many  disadvantages 
under  which  its  hasty  publication  is  now  undertaken. 
It  doubtless  contains  many  defects. 

For  the  method  of  analysis  given  in  Chapter  V.,  I 
am  indebted  to  Captain  E.  C.  Boynton,  U.  S.  Army, 
late  Professor  of  Chemistry  in  the  University  of  Mis- 
sissippi. 

Q.  A.  GILLMOEE, 

Brig.' General. 

Hea  J-QuARTEHs,  Dept.  of  the  South,  ]^ 
Poet  Royal,  S.  0.,  June  15,  1863.  J 


PREFACE  TO  THE  FOUETH  EDITIOE". 


In  preparing  the  fourth  edition  this  work  for  the  press,  it 
has  been  thought  proper  to  give,  in  an  Appendix,  brief  descrip- 
tions of  the  two  methods,  one  by  hand  and  the  other  by 
machinery,  followed  in  making  the  several  qualities  of  Portland 
cement  concrete,  applied,  for  various  purposes,  in  the  construction 
of  the  fortifications  on  Staten  Island,  'New  York  Harbor,  of 
which  the  author  has  charge  as  superintending  Engineer. 

The  special  information  given  has  been  derived  from  the  ex- 
perience of  two  working  seasons — 1870  and  1871 — and  all  the 
data  with  regard  to  the  cost  and  proportions  of  the  constituent 
ingredients — the  cement,  lime,  sand,  gravel,  and  broken  stone — 
as  w^ell  as  the  cost  of  the  finished  concrete  in  position,  may  be 
relied  upon  as  correct,  within  reasonable  limits. 

The  Appendix  also  contains  a  description  of  the  new  concrete 
mixer,  in  use  on  the  works,  a  drawing  of  which  serves  as  a 
frontispiece  to  this  edition. 

A  new  and  carefully  prepared  index  has  been  inserted  in 
place  of  the  old  one,  and  the  work  has  been,  in  other  respects, 
essentially  revised  and  improved. 

Q.  A.  GILLMOEE, 

Bvt.  Mc0 or- General,  U.S.A.. 

New  York,  January,  1872. 


STIj"OPSIS  OF  CONTElNrTS. 


CHAPTER  I. 

Geographical  and  geological  localities  of  hydraulic  cement  in  the  United 
States. — Analysis  of  various  specimens  from  Virginia,  New  Jersey,  New 
York,  Massachusetts,  and  Mississippi.   Pages  15-27. 

CHAPTER  II. 

Precautions  employed  in  procuring  cements  for  testing. — Appliances  for 
testing  the  transverse  strength,  hardness,  and  adhesive  properties  of 
mortars.   Pages  28-35. 

CHAPTER  III. 

Rosendale  cement. — Location  and  capacity  of  the  manufactories. — Cement 
works  at  Shepherdstown,  Va. — The  Round  Top  cement  works  near 
Hancock,  Md. — The  Cumberland  cement  works. — The  James  River 
cement  works. — The  works  at  Utica,  La  Salle  Co.,  111. — Sandusky,  Ohio. 
Louisville,  Ky. — Kensington,  Conn.,  and  Akron,  Manlius,  and  Chitte- 
nango,  N.  Y. — The  Portland  and  the  Roman  cements.    Pages  36-66. 

CHAPTER  IV. 

Common  lime,  and  lime  mortars. — Hydraulic  limes  and  cements. — ^Natural 
pozzuolana  and  trass. — Ar^nes. — Artificial  hydraulic  cement  and  lime. 
The  use  of  alkaline  silicates. — Silicatization. — Endurance  of  hydraulic 
mortars  and  betons  in  sea- water. — Opinions  thereon  of  Marshal  Vaillant, 
Inspector-General  Noel,  MM.  Ravier,  Feburier,  Vicat,  and  other  French 
authorities.   Pages  67-109. 

CHAPTER  V. 

Diversified  character  of  limestone  beds. — Method  of  testing  the  stone  ex- 
perimentally.— Qualitative  and  quantitative  analysis. — Analyses  of  vari- 
ous cements,  limes,  trass  and  pozzuolana. — Kilns  for  burning  cement  and 
method  of  burning. — EflTect  of  varying  the  intensity  and  duration  of 
the  heat. — Preservation  and  restoration  of  cements.    Pages  110-173. 


14 


CONTENTS. 


CHAPTER  VI. 

Mortar  defined. — Aggregates. — The  use  of  sand. — Method  of  slaking  hme. — 
Action  of  hydrates  in  air  and  under  water. — Mill-made  mortar. — Hand- 
made mortar. — Composition  and  cost  of  mortar  used  in  Forts  Rich- 
mond, Tompkins,  and  Warren. — Pointing  mortar. — Interior  and  exterior 
plastering.   Pages  174-222. 

CHAPTER  VII. 

Concrete  or  beton. — How  made  and  used. — How  laid  under  water. — Com- 
position and  cost  of  concrete  used  at  Forts  Richmond,  Tompkins,  and 
Warren. — Use  of  concrete  at  Toulon,  Algiers,  Marseilles,  Cherbourg, 
Dover,  Alderney,  etc. — Tables  giving  strength  of  various  kinds  of  con 
Crete.    Pages  223-258. 

CHAPTER  VIII. 

Neat  cement  made  semi-fluid  with  excess  of  water. — Superiority  of  Portland 
over  the  natural  quick  cements,  when  so  employed.— Comparison  of 
Portland  and  Roman  cements. — xldhesive  properties  of  American  ce- 
ments.— Transverse  strength  of  various  mortars.   Pages  259-293. 

CHAPTER  IX. 

Mural  efflorescences.— Induration  of  mortars  of  fat  lime. — Theory  of  hydrau- 
lic induration. — The  hardening  by  artificial  means  of  stone,  brick, 
mortar,  etc.    Pages  293-316. 

APPENDIX. 

Description  and  cost  of  several  kinds  and  qualities  of  concrete  used  in  the 
construction  of  the  fortifications  on  Staten  Island,  New  York  Harbor, 
during  the  years  1870  and  1871.— Description  of  new  concrete  mixer. 
Page,  317-326. 


A  PEACTICAL  TEEATISE 

ON 

LIMES,  HYDRAULIC  CEMENTS,  AOT)  MORTARS. 


CHAPTEE  I. 

INTRODUCTION. 

1.  Nature  has  supplied  us  with  limestones  in  great  profusion 
and  endless  variety.  Those  suitable  for  common  lime  are  so 
widelj  diffused,  and  have  such  an  extensive  development  in  this 
country,  that  no  attempt  will  be  made, — nor  An  abimdance 
would  it  be  consistent  with  the  character  and  stone?SThe™^' 
scope  of  a  work  devoted  to  the  consideration  of   United  states. 

"  mortars,"  even  under  the  most  comprehensive  signification 
of  that  term, — to  particularize  the  numerous  localities  where 
its  manufacture  is  extensively  and  successfully  carried  on. 

2.  Impure  or  compound  limestones,  possessing  the  property 
of  hardening  under  water  after  being  calcined,  and  reduced  by 
slaking,  or  by  the  aid  of  mechanical  means,  to    Compound  lime- 
the  state  of  paste,  although  more  rare  than  the  g^^^^emurir' 
common  limestones,  nevertheless  occur  in  numer-  caiities. 

ous  localities  in  the  United  States ;  and  from  the  great  and 
peculiar  value,  as  a  cementing  material  for  submarine  and  sub- 
terranean constructions,  of  the  mortars  derived  xVom  them, 
they  merit  a  more  detailed  notice. 

3.,  The  most  extensive  beds  have  thus  far  been  discovered  in 
the  valleys  of  the  great  Appalachian  chain  of  mountains,  as 
they  traverse  the  States  of  New  York,  New  Jersey,  Pennsyl- 


16 


PRACTICAL  TREATISE  ON  LIMES, 


vania,  Virginia,  Tennessee,  and  the  northern  portions  of 
Georgia  and  Alabama.  They  are,  however,  by  no  means  con- 
fined to  those  States,  but  have  been  found  to  some  extent  in 
the  northern  terminus  of  this  range,  as  it  passes  through  Massa- 
chusetts and  Vermont,  at  the  forks  of  the  Kennebeck,  and 
other  places  m  Maine,  and  in  the  northern  counties  of  Missis- 
sippi. In  a  westerly  direction,  and  beyond  the  lateral  limits 
of  the  great  Appalachian  Yalley,  in  the  western  regions  of 
New  York,  Pennsylvania,  Yirginia,  and  Tennessee,  as  well  as 
in  Kentucky,  Ohio,  Indiana,  and  Illinois,  the  same  kind  of 
stone  exists  in  numerous  and  extensive  deposits. 

4.  There  is  no  geological  formation  to  which  the  term 
"  hydraulic  lime"  or  "  hydraulic  cement"  can  with  propriety 
be  exclusively  applied,  inasmuch  as  we  find  none  which, 
over  extensive  areas,  and  in  localities  widely  separated,  is  capa- 
The  character  of  furnishing  uniformly  either  the  one  or  the 

stone  suitable  for  other  of  these  products.  All  sedimentary  rocks 
cement^Ts^very^  are  noted  for  the  marked  variations  in  their 
variable.  lithological  characters,  within  very  limited  areas, 

owing  to  the  existence  of  local  causes,  affecting  the  conditions 
of  their  deposition.  This  is  specially  the  case  with  those 
impure  limestones  of  which  the  composition  is  such  as  to  render 
them,  as  an  exceptional  class,  suitable  for  hydraulic  mortars, — a 
circumstance  due  to  their  peculiar  geological  position.  They 
The  usual  ingre-  usually  contain,  in  widely  varying  proportions, 
dients  the  same,  carbonate  of  lime,  carbonate  of  magnesia,  silica, 
alumina,  oxide  of  iron,  and  a  small  amount  of  alkali,  and  are 
generally  comprised  in  the  beds  of  passage  between  deposits 
that  are  purely  silicious  or  argillaceous,  and  those  that  are 
purely  calcareous  or  dolomitic.  They  therefore,  in  the  general 
case,  derive  their  character  from  the  contiguous  underlying  and 
overlying  rocks,  and  approximate  more  intimately  to  the  one 
or  to  the  other,  in  proportion  as  the  causes  operating  during 
the  period  of  formation  unduly  favored  its  deposition.  If  a 
limestone,  for  example,  was  formed  upon  a  sandstoTie,  by  the 


HYDRAULIC  CEMENTS,  AND  MORTARS.  17 


gradual  and  progressive  subsidence  of  calcareous  particles, 
commenced  and  carried  on  before  the  deposition  of  the  silicious 
matter  was  completed,  the  intermediate  beds  created  by  this 
mingling  process  would  be  a  silicious  limestone,  with  propor 
tions  depending  on  the  manner  of  deposition,  and  the  nature 
and  extent  of  the  causes  by  which  it  was  produced  and  regu- 
lated. It  could  be  uniform  only  while  those  causes  remained 
fixed  and  persistent.  The  intervention  of  local  disturbances  of 
whatever  extent  or  character,  tending  to  hasten,  retard,  or  ran 
der  intermittent  the  deposition  of  either  of  the  principal  ingre- 
dients, would  of  course  modify  their  proportions,  and  materi- 
ally afi(ect  the  character  and  properties  of  the  compound  rock. 

5.  Observations  show  that  the  argillaceous  and  argillo- 
magnesian  limestones  of  the  United  States  are  characterized, 
in  an  eminent  degree,  by  variations  in  composition,  due  to 
such  causes ;  and  that  these  variations  frequently,  and,  in  fact, 
generally,  occur  within  very  short  distances. 

6.  At  the  base  of  the  Lower  Silurian  System  we  find  the 
Potsdam  Sandstone,  the  lowest  known  fossiliferous  rock,  and 
interesting  in  this  connection  from  the  fact  that  it,  in  a  mea- 
sure, imparts  hydraulic  character  (by  supplying  the  silica)  to 
the  calcareous  deposits  restine^  upon  it.  In  'New 

^     ,  .  ,   ^       .        r,  .The  Potsdam 

York,  this  sandstone  is  a  nrm  quartzose  rock;   Sandstone  under- 

while,  in  some  portions  of  the  West,  the  cohesion  caicar^ousTed^s 
between  the  particles  is  so  slight  that  it  can  be   possessing  hy- 

^  draulicity. 

easily  crumbled  in  the  hand.  It  occurs  of 
various  shades  of  yellow,  red,  and  gray,  approaching  to  white, 
and  is  most  intimately  related  to  the  calcareous  beds  which 
underlie  it.  In  many  places,  it  gradually  passes  into  easily 
recognized  compact  magnesian  limestone,  sometimes  alternating 
with  the  calcareous  beds  above.  This  sandstone  corresponds 
to  Formation  I.  of  Prof.  Rogers'  classification  of  the  rocks  of 
Pennsylvania  and  Virginia. 

7.  The  next  rock  in  the  ascending  series  belongs  to  Forma- 
tion II.,  known  as  the  calcareous  "  sandrock."  or,  more  com- 


18 


PEACTICAL  TEEATISE  ON  LIMTSfc 


monly,  calciferous  group,"  which,  in  both  composition  and 
age,  must  be  regarded  as  intermediate  between  tne  Potsdam 

"  Calciferous   Sandstone  and  the  purer  limestones  above,  viz. . 

Group."  the  Chazy,  Bird's  Eye,  Black  Eiver,  and  Tren- 
ton Groups.  It  is  the  oldest  known  fossiliferous  limestone,  is 
ealcareo-silicious  in  character,  as  its  name  indicates,  and  is  the 
lowest  member  of  the  series  capable  of  yielding  either 
hydraulic  lime  or  cement.  In  many  localities,  it  exhibits  the 
water-lined  lamin?e  of  deposition  in  a  marked  and  conspicuous 
degree. 

Three  distinct  masses  of  this  rock  are  usually  observed 
wherever  it  presents  a  fully  developed  outcrop. 

8.  The  lowest  beds  are  highly  silicious,  and  in  the  eastern 
portions  of  the  United  States,  where  it  has  been  most  examined, 
quite  compact,  being  undoubtedly  produced  by  a  partial  con- 
tinuation of  the  Potsdam  Sandstone  deposit,  carried  on  simul- 
taneously with  that  of  the  calcareous  matter,  the  composition 
of  the  rock  showing  a  notable  excess  of  the 

Its  lower^  middle,  ^ 
and  upper  subdi-  former. 

^^^^*^°^*  9.  The  middle  beds  appear  to  comprise  a 

variable  mixture  of  yellowish  sand  and  carbonate  of  lime,  pre- 
senting, when  newly  broken,  a  gritty  and  sparklm^:  fracture. 
They  are  those  to  which  the  term  "  Calciferous  Sandrock"  is 
usually  applied. 

10.  The  uj)per  or  superior  mass  more  nearly  approximates 
m  character  to  the  limestones  above,  and  is  very  frequently 
intermixed  with  argillaceous  matter.  The  appearance  of  a 
recent  fracture  is  granular  and  sparkling,  and  often  exhibits  a 
sub-crystalline  structure.  This  rock,  however,  assumes  at  dif- 
ferent points  a  remarkable  diversity  in  both  its  physical  appear- 
ance and  its  chemical  composition.  It  is  synonymous  with 
the  Barnegat,  Newburgh,  Warwick,  Oolitic,  and  Slaty  lime- 
stones, the  Transition  Sandrock  of  Eaton  and  the  Fucoidal 
Layer?.,  and  with  the  Magnesian  limestones  of  the  West. 

Jl.  The  purer  calcareous  beds  which  rest  immediately  upoD 


HYDRAULIC  CEMENTS,  AND  MORTAES.  19 


the  "  Calciferous  Group"  also  belong  to  Formation  II.  of  Prof. 
Rogers'  classification,  and  are  known  at  different  points  as  the 
Black  River  limestone,  the  base  of  the  Trenton  limestone,  the 
Mohawk,  Bird's  Eye,  Bald  Mountain,  Blue,  and  Chazj  lime- 
stones, the  Transition  Limerock  of  Eaton,  Blue  limestone  of 
Kittatinny  Yalley,  Pennsylvania ;  and,  in  the  West,  as  the  Fos- 
siliferous  limestones,  and  the  Blue  limestones  and  marls.  These 

beds  are  frequently  connected  very  intimately 

.11  1  .1  11  1  •'      The  calcareous 

With  the  members  oi  the  group  below,  and,  m    beds  resting  on 
numerous  localities,  possess  in  suitable  propor-  Group''^suUaU^^ 
tions,  and  in  proper  combination,  those  ingre-    for  hydraulic 
dients  which  confer  the  hydraulic  property. 

12.  It  is  unnecessary  for  our  purpose,  in  a  work  like  this, — 
in  which  rocks  of  a  particular  class,  and  bearing  a  close  resem- 
blance to  each  other  in  their  general  features,  are  discussed 
specially  with  reference  to  their  adaptation  to  a  particular  use, — 
that  all  the  technicalities  of  a  strictly  geological  classification 
should  be  kept  constantly  in  view.  It  will  be  Between  the 
sufl&cient  to  intimate,  in  brief  terms,  that  among  ^tone  and^^e^' 
those  deposits  lying  above  the  Potsdam  Sand-    utica  Slate,  many 

,  ,    ,  *      ,  .       ^,  .  argillo-magnesian 

stone,  and  below  the  Utica  blate  or  its  corre-  deposits  possess 
spending  member,  all  of  which  are  comprised  in  l^y^irauhc  energy. 
Prof.  Rogers'  Formation  II.,  are  found  in  numerous  places 
extensive  beds  of  argillo-magnesian  limestone,  possessing  the 
hydraulic  energy  in  a  high  degree ;  and  that  these  beds  occur 
sometimes  higher,  and  sometimes  lower  in  the  series,  as  deter- 
mined by  causes  operating  during  the  period  of  their  forma- 
tion. They  have  an  extensive  development  in  the  United 
States,  particularly  along  the  great  Appalachian  range. 

13.  In  the  State  of  JSTew  York,  they  occupy  a  narrow  belt 
along  the  eastern  portion  of  the  State,  extending  from  the  Ver- 
mont line  in  a  southerly  direction  through  Williamstown,  Leba- 
non Springs,  Pine  Plains,  Barnegat,  and  ISTew-  Geographical 
bur2:h  :  thence  stretchino:  in  generally  parallel    l<^?^i\*^es  of  the 

^  .  principal  outcrops 

strips  in  a  southwesterly  direction  towards  the    in  New  York. 


20 


PEACTICAL  TEEATISE  ON  LIMES, 


New  Jersey  State  xine,  which  it  crosses  between  Union ville 
and  the  Long  Pond.  The  same  stone  is  also  brought  to  the 
surface  repeatedly  in  New  York,  in  the  counties  of  Montgom- 
ery, Herkimer,  Oneida,  Lewis,  Warren,  Clinton,  and  Jefferson. 
In  but  few  of  the  localities  mentioned  is  the  stone  manufac- 
tured into  hydraulic  cement,  and  in  none,  perhaps,  have  its  full 
capabilities  in  this  regard  been  ascertained  by  adequate  experi- 
mental tests. 

14.  Within  the  State  of  New  Jersey  this  formation  continues 

its  course,  exhibiting  extensive  outcrops,  lying  generally  within 

the  limits  of  a  belt  or  zone  from  twenty  to  twenty-five  miles 

in  width,  which  intersects  the  Delaware  River 
In  New  Jersey.      .  ...        ^  .  „  .iiti-t 

m  the  vicinity  oi  its  coniluence  with  the  Lehigh. 

It  then  crosses  into  the  State  of  Pennsylvania,  and  spreads 
itself  over  a  large  tract  in  the  eastern  portion  of  that  State, 
southeast  of  Kittatinny  valley,  in  Lehigh,  Berks,  Chester,  Lan- 
caster, and  York  counties,  and  elsewhere. 

15.  In  Virginia  the  limestones  of  this  formation  also  exist  in 
numerous  and  extensive  beds  in  the  counties  of  Rockingham, 
Botetourt,  Roanoke,  Washington,  Rockbridge,  Page,  Augusta, 

^  ^.  _  Giles,  and  Shenandoah.  Cement  from  the  James 
River  and  KanaAvha  Canal  has,  for  several  years, 
been  manufactured  at  Balcony  Falls,  Rockbridge  County.  At 
the  present  time  cement  for  constructing  the  Covington  and 
Ohio  Railroad  is  derived  from  Dunlop's  Creek,  a  tributary  of 
the  James  River,  a  few  miles  above  Covington.  There  are 
three  cement  manufactories  on  the  Potomac  River:  one  at 
Shepherdstown,  Ya.,  another  three  miles  above  Hancock,  Md., 
and  another  at  Cumberland,  Md.  From  the  present  state  of 
our  knowledo;e,it  would  be  inferred  that  the  beds 

TheYirginianand    ^    ^       .  i  .     «  •        .    -^r-     •   •  i 

Pennsyivaniande-   belonging  to  this  formation  m  Virginia  and 

to  bforsuprfor    Pennsylvania  are  better  calculated  to  furnish  a 

quality  to  those  reliable  cement  than  those  found  in  the  more 
farther  North.  t     tvt       -xr  ^ 

northern  parts  of  the  range.    In  New  York, 

one  member  of  the  series — the  Black  River  limestone — was 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


21 


formerly  made  into  cement  at  and  near  Galesville,  Washington 
County,  for  the  Champlain  Canal.  At  Point-aux-Koches,  on 
Lake  Champlain,  a  bed  of  it  five  to  six  feet  in  thickness  exists, 
which  possesses  a  good  degree  of  hydraulic  energy,  but  has 
never  been  manufactured  for  the  market.  The  same  stratum 
has  been  found  to  yield  only  hydraulic  lime  in  some  localities, 
and  has  been  used  for  that  purpose  at  Lowville,  Lewis  Coun- 
ty,  N.  Y. 

16.  Among  the  many  analyses  that  have  from  time  to  time 
been  made  of  specimens  from  the  various  deposits  of  these 
limestones,  those  in  Table  1.  have  been  selected  from  the  most 
reliable  sources  of  information  which  were  at  command.  It  is 
proper  to  remark  in  this  connection,  that  those  given  in  the 
table, — having  been  derived  from  State  Geological  Reports, 
principally,  for  the  general  purposes  of  which  they  are  doubt- 
less sufficiently  exact, — ought  not,  perhaps,  to  be  implicitly 

relied  upon,  as  the  basis  of  any  special  or  criti-     ,    ,  .  „ 

^     ^  .  .      Analysis  of  the 

cal  research  upon  the  subject  of  hydraulic  above-mentioned 
mortars  and  the  theory  of  sub-aqueous  indu- 
ration.   None  of  them  show  the  presence  of  either  potash  or 
soda  in  any  form.    It  is  well  known,  however,  that  the  salts 
of  both  these  substances  exist  in  some  of  the  quarries  exam- 
ined, and  it  is  fair  to  infer,  from  the  close  resemblance  other- 
wise preserved  in  the  nature  and  proportion  of   g^^^  potash 
the  constituent  parts,  that  adequate  tests  would    probably  exist  in 
detect  a  notable  quantity  in  all.  The  Rosendale 
cements  contain  them.    An  easy  process  for  detecting  their 
presence,  and  measuring  their  quantity,  has  yet  to  be  dis- 
covered, which  may  account  for  the  fact  that    ^^^^  ^^^^^^ 
their  existence  in  this  class  of  rocks  is  so  very    tected  and  mea- 
generally  ignored.* 

*  M.  Fred.  Kuhlmann,  Professor  of  Chemistry  at  Lille,  and  Corresponding  Mem- 
ber of  the  lustitut  de  France,  submitted  a  report  to  the  Academy  of  Sciences  of 
France  in  1841,  from  which  the  following  extract  is  taken.  The  subsequent  wri- 
tings of  M.  Kuhlmann,  down  to  a  period  quite  recent,  sustain  the  opinions  here 


22 


PRACTICAL  TREATISE  ON  LIMES, 


TABLE  L 

AlfALTSIS    OP    SEVERAL    OF   THE    OLDEST   FOSSILirEROtJS   LIMESTONES  OCCUPYING 
POSITIONS  BETWEEN  THE  POTSDAM  SANDSTONE  AND  THE  UTICA  SLATE. 


I—,  cc 

c  ^ 


Cabonate  of  lime  

Carbonate  of  magnesia  

Alumina  and  oxide  of  iron. . 

Silica  

Sulphuret  of  iron  

Carbonate  of  potash  and  soda 
Water  and  loss  


54. 

42.5 
1.5 
1.5 


52. 

37.5 
1.5 
8.5 


46.5 
34.5 

4. 
13. 

1. 

1. 


52. 

41.8 
1.2 
4.7 


54. 
42.5 
.7 
2.4 


52.9 
44. 
.6 
2.2 


53. 
41.1 

1. 

3.2 


1.7 


53.5 
38.8 
.7 
6.3 


54.9 

34. 
2.1 
7.5 


1.5 


53.6 
41.6 
1.4 
3.4 


53.3 
22.6 
1.7 
20.T 

M 
1.6} 


17.  After  passing  the  argillo-magnesian  limestones  associated 

^   ^       with  the  "  Calciferous  Sandrock,"  and  inter 
JNo  cement  stone  ' 

between  the  utica    mediate  in  lithological  features  between  this 

Slate  and  the  Nia-  i        t    -i  t        ,  ^ 

gara  Group  of  the  rocK  and  the  purer  limestones  above,  we  meet 
Ontario  Division,  ^.^j^  calcareous  deposit  suitable  for  hydraulic 
cement  until  we  reach,  in  the  ascending  order,  the  Niagj-ra 
Group  of  the  Ontario  Division,  among  the  beds  of  pa.c>e.^ge 
from  the  shale  to  the  limestone  of  that  group.  Here  i<'  found 
an  argillaceous  limestone  brought  to  the  surface  reyc/'chdlj  in 
the  State  of  ISTew  York,  in  Wayne  County,  and  ^ ;  t^iC  towns 
of  Kose,  Williamson,  and  Ogden,  in  Monroe  UrcAtj.  This 

expressed  as  to  the  general  prevalence  of  the  alkaline  salts  i^-  '/.e  hydraulic  limea 
and  cements  of  Europe. 

Extract. — In  speaking  of  the  nature  of  the  efflorescences  t^on  walls,  he  says . 
"  Mes  investigations  sur  ce  point  m'ont  permis  de  constar^rt  la  presence  de  la  po- 
tasse  ou  de  la  soude  dans  la  plupart  des  calcaires  de  diversujs  epoques  geologiques, 
et  de  justifier  I'existence  de  ces  alcalis  dans  les  vegetaux  qui  croissent  sur  un  sol  cal- 
cftire."  M.  K.  also  analyzed  the  cements  of  Pouilly,  Vassy-les-Avallon,  Bou- 
logne, and  the  Roman  cement  from  the  Septaria,  taken  from  the  banks  of  the 
Thames,  and  found  potash  in  all  of  them,  notwithstanding  the  confirmed  opinirjn 
of  chemists  that  they  contain  no  alkahne  ingredient.  American  cements  conth,*u 
chlorides  of  potassium  and  sodium  generally,  sometimes  as  high  as  V  per  cent 


HYDEATJLIC  CEMENTS,  AND  MORTARS.  23 


deposit  exposes  very  good  cement  stone  in  Orleans  County,  at 
Oak  Orchard  Creek,  town  of  Shelby,  and  at  Farwell's  Mills, 
town  of  Clarendon ;  also  in  Niagara  County,  at  Lewiston. 
Among  these  beds  of  passage,  only  those  occupying  a  central 
position  can  be  relied  upon  for  hydraulic  mortar,  the  layers 
above  being,  as  a  general  thing,  too  highly  charged  with  car- 
bonate of  lime,  while  those  below  contain  too  much  clay. 

18.  Overlying  the  Niagara  Group,  we  find,  in  the  Helder- 
berg  division,  a  limestone  among  the  upper  beds  of  the  Onon- 
daga Salt  group,  sometimes  called  the  Magnesian  u  Magnesian  De- 
deposit  of  that  group,  which  furnishes  nearly  all  ^^daga^sllt^ 
the  hydraulic  cement  manufactured  in  the  group, 
western  part  of  the  State  of  New  York.  It  appears  on  the 
eastern  shore  of  the  Cayuga  Lake,  and  further  west,  in  Phelps 
and  Manchester  townships,  Ontario  County,  at  Williamsville, 
Grand  Island,  and  Akron,  Erie  County.  At  East  Yienna  it 
has  been  used  for  cement,  and  at  Akron  a  manufactory  of 
some  extent  is  in  operation  now. 

At  Morgantown,  Genesee  County,  and  at  Black  Rock,  Erie 
County,  the  limestones  of  this  group  have  an  extensive  devel- 
opment in  connection  with  those  of  the  Water  Lime  Group 
proper.  Its  full  thickness  is  seen  at  the  Falls  of  Falkirk.  It 
underlies  the  village  of  Caledonia,  Livingston  County,  ex- 
tending thence  easterly  towards  the  Genesee  River,  and,  re- 
appearing on  the  other  side  of  that  stream,  is  found  at  Mendon, 
Monroe  County,  and  other  neighboring  localities. 

19.  Beyond  the  limits  of  the  State  of  New  York,  the  layers 
above  mentioned  are  not  found  possessing  such  prominent 
features  as  to  entitle  them  to  a  distinct  and  separate  descrip- 
tion, but  are  included  in  the  contiguous  groups  under  a  more 
general  classification. 

20.  Overlying  the  Onondaga  Salt  Group,  in  regular  suc- 
cession, is  found,  along  the  great  Appalachian  range,  the 
Tentaculate,  or  Water  limestone,  from  which  a  »  Tentaculate"  or 
very  large  proportion — perhaps  nine-tenths — of  p^^^^^^ 


24 


PRACTICAL  TEEATISE  ON  LIMES, 


tlie  hydraulic  cement  manufactured  in  the  United  States  is  de- 
rived. It  appears  to  be  wanting  in  the  West- 
Geographical  lo-  ^ 
caiities  of  the  ern  States,  or  to  have  been  replaced  hj  the 
principal  beds.  q^j^  limestone  of  Ohio.  In  E  ew  York,  it  is 
found  in  large  quantities  in  Oneida,  Onondaga,  Madison,  Ul- 
ster, Sullivan,  and  Erie  Counties.  Its  principal  deposit  is  in 
Ulster  County,  where  it  furnishes  the  celebrated  Rosendale 
cement,*  so  extensively  used  on  the  government  works  on  the 
Atlantic,  Gulf,  and  Pacific  coasts,  and  along  the  northern 
frontier.  It  is  quarried  for  cement  at  Manlius  and  Fayette- 
ville,  Onondaga  County,  and  Chittenango,  Madison  County. 
The  cements  from  these  localities  vary  very  much  in  quality. 
A  cement  manufactory  is  also  carried  on  at  Lockport,  Niagara 
County.  The  stone  that  may  be  used  for  cement,  occurring 
frequently  along  the  line  of  the  Erie  Canal,  occupies,  with 
some  local  exceptions,  two  geological  positions  quite  distinct 
General  character  from  each  other.  The  lowest  layers  are  mostly 
stone^afo^The  Confined  to  the  beds  of  passage  from  the  shale 
Erie  Canal.  of  the  Niagara   Group   to  the  purer  lime- 

stones above,  while  the  others  are  similarly  situated  with  refer- 
ence to  the  marls  and  shales  of  the  Onondaga  Salt  Group  and 
the  purer  calcareous  beds  which  overlie  them.  In  either  po- 
sition, great  care  is  requisite  in  selecting  the  stone  for  burning, 
the  best  cement  being  generally  confined  to  the  middle  of  these 
beds  of  passage — those  below  being  too  argillaceous,  those 
above  too  calcareous. 

21.  Reserving  a  more  detailed  and  minute  description  of  the 
Ulster  County  deposits  for  a  subsequent  part  of  this  work,  we 
will  here  simply  state  that  they  are  mostly  found  within  the 
limits  of  a  narrow  belt,  scarcely  one  mile  in  width,  skirting  the 
Principal  deposits  northwestern  base  of  the  Shawangunk  Moun- 
of  "  Rosendale      tains,  alouff  the  line  of  the  Delaware  and  Hudson 

Cement"  stone.  ^ 

Canal,  in  the  valley  of  Rondout  Creek.  They  are 

*  Named  from  the  town  of  Rosendale,  in  which  the  cement  was  first  discovered 
and  manufactured,  during  the  construction  of  the  Delaware  and  Hudson  Canal. 


HYDEAULTC  CEMENTS,  AND  MOETAES. 


25 


not,  however,  confined  to  this  locality,  but  can  be  traced  in  a 
southwesterly  direction  through  Ulster  and  Sullivan  Counties  to 
the  State  Line  at  Carpenter's  Point,  and  thence,  within  the  State 
of  New  Jersey,  in  a  narrow  strip  along  the  left  bank  of  the 
Delaware  Kiver,  to  Walpack's  Bend,  where  they  cross  over  in- 
to the  State  of  Pennsylvania.  In  a  northerly  direction,  this 
rock  has  not  been  distinctly  recognized  east  of  the  Hudson 
Eiver.  At  the  mouth  of  Eondout  Creek  the  belt  takes  a  turn 
due  north,  and  can  be  correctly  followed  along  the  right  bank 
of  the  Hudson,  a  distance  of  five  or  six  miles,  with  occasional 
glimpses  of  it  in  detached  masses  ten  or  twelve  miles  higher 
up.  Except  in  Ulster  County,  towards  the  northern  terminus 
of  the  range,  these  beds  have  not  been  manufactured  into 
cement,  and  have  not,  it  is  believed,  been  very  critically  ex- 
amined with  that  view. 

22.  The  only  limestone  in  Massachusetts  that  has  ever  been 
employed  for  hydraulic  mortar  is  that  at  Paine's  Quarry,  West 
Springfield.  It  is  said  to  be  very  good  hydraulic  lime,  and 
contains,  by  analysis,  .93i  of  carbonate  of  lime.  Cement  stone  in 
.5/o-  of  argillaceous  clay,  and  less  than  .1  of  car-  Massachusetts, 
bonate  of  magnesia.  Another  hydraulic  limestone  that  has 
been  tried,  but  never  worked,  is  found  in  the  bed  of  the  Chi- 
copee  Piver,  just  below  the  Chicopee  Factory.  It  contains 
.S6j\  of  carbonate  of  lime,  and  .13y\  of  argillaceous  clay. 
Both  of  the  stones  just  mentioned  are  fetid  and  partially  bitu- 
minous. They  belong  to  the  new  Red  Sandstone  formation. 
Nodules  of  Septaria  are  found  on  the  Chicopee  and  at  Cabot- 
ville,  and  an  argillaceous  limestone  at  West  Springfield,  that 
are  pronounced  by  Prof.  Hitchcock  to  furnish  a  cement  as 
energetic  as  the  "  Poman  "  The  following  table  contains  their 
analysis ; 


26 


PRACTICAL  TREATISE  ON  LIMES, 


TABLE  11. 


Argillaceous  limestone,  West 


Springfield. 


Septaria  from 
the  Chicopee. 


Septaria  from 
Cabotville. 


1st  Sample.      2(1  Sample. 


Carbonate  of  lime  

Carbonate  of  magnesia . . 

Silica  and  alumina  

Oxide  of  Iron  


46.06 
27.35 
20.97 
5.62 


43.69 
39.35 
13.57 
3.39 


30.81  26.04 

18.33  13.45 

45.33  54.00 

5.53  6.51 


The  2d  sample  from  West  Springfield  is  but  feebly  hydraulic. 
23.  East  of  Massachusetts,  cement  stone  is  found  in  some 
localities,  but  is  not  used  for  hydraulic  mortar.    Deposits  exist 
r««^^r,f  of^r,n  ir.    ^t  Machlas  aud  at  the  forks  of  the  Kennebec 


locality,  analyzed  several  years  ago  by  Dr.  Charles  T.  Jackson, 
contained  .54:yV  of  carbonate  of  lime,  .05  of  carbonate  of 
magnesia,  .028  of  carbonate  of  iron,  .024  of  silicate  of  iron  and 
manganese,  .27  of  silica,  .082  of  alumina. 

24.  Near  Kensington,  Conn.,  a  good  cement  stone  is  found, 
Cement  stone  in     which  is  manufactured  to  a  limited  extent  for 


at  the  Falls  of  the  Ohio  Kiver. 

25.  The  following  extract  from  the  forthcoming  work  of  the 
Cement  stone  in  State  Geologist  of  Mississippi,  gives  the  analysis 
Mississippi.  cement  stones  found  in  that  State  in  Tish- 

amingo  County  :  "  E'o.  1  furnishes  a  cement  which  sets  as 
rapidly  as  Plaster  of  Paris  and  becomes  very  hard.  'No.  2  dif- 
fers from  No.  1  in  requiring  more  time  to  harden."  See 


Cement  stone  in 
Maine. 


Piver,  Me. ;  a  specimen  from  the  last-named 


Table  III. 


TABLE  III. 


Silica  and  insoluble  Silica  

Potash  

Lime  

Magnesia  

Protoxide  of  iron  

Alumina  

Phosphoric  acid  

Carbonic  acid  

Water,  organic  matter,  and  loss 


No.  1. 

54.201 
.473 
23.247 
.788 
.903 
1.064 
Trace 
15.572 
3.752 


No.  2. 

35.281 
.348 

32.603 
.630 
.158 
1.914 


27.643 


HTDEAULIC  CEMENTS,  AND  MOETAES. 


27 


26.  No  deposits  of  hydraulic  lime  or  cement  stone  are  found 
on  the  Pacific  coast,  although  inquiries  to  a  considerable  extent 
have  been  made. 

The  Eosendale  cements  are  depended  upon  for  hydraulic 
mortar. 


28 


PEACTICAL  TREATISE  ON  LIMES, 


CHAPTEK  II. 

27.  The  method  pursued  in  testing  the  mortars  which  fur- 
nish the  basis  of  all  tables  introduced  into  this  report,  with  the 
exception  of  those  compiled  from  the  labors  of  others,  for  the 
purpose  of  reference  and  comparison,  is  briefly  as  follows : 

28.  With  some  exceptions  that  will  be  pointed  out  in  the 

proper  place,  all  the  samples  of  hydraulic  ce- 
The  cements  not  ,      ^  i     .  ,  i  .     •  i 

prepared  under       ment  not  prepared  at  the  manuiactories,  under 

the  writer's  super-    ^-^^  personal  supervision  of  the  writer  or  an 

vision  were  sam-  ^  ^ 

pies  from  cargoes    affcnt  appointed  by  him,  were  obtained  from 

in  the  market.  ^  .    \,  i       ,  .  . 

cargoes  m  the  market,  by  opening  several  casks 
selected  at  random,  and  taking  two  or  three  pounds  from  each. 
This  precaution  was  adopted  in  order  to  secure,  beyond  a  ques- 
tion, samples  of  an  average  quality  from  the  respective  cargoes, 
and  for  the  time  being,  of  the  respective  cements  furnished  bj 
the  several  manufactories. 

29.  Identity  in  the  composition  and  properties  of  samples  of 
the  same  brand,  obtained  from  different  cargoes  and  at  differ- 
ent times,  was  never  assumed.  An  examination  and  compari- 
son of  the  tables  throughout  this  work,  clearly  establish  the 
necessity  of  this  precaution.  As  some  manufacturers  habitu- 
ally grind  their  stone  finer  than  others,  and  as  there  is  consid- 
erable difference,  in  this  particular,  in  cement  from  the  same 
establishment  manufactured  at  different  times,  due  in  part  to 
the  difiiculty  with  which  a  high  degree  of  pulverization  can  be 
secured  with  newly-dressed  millstones,  but  principally  to  negli- 
gence on  the  part  of  the  miller,  it  was  important  that  this  cause 


HYDEAULIC  CEMENTS,  AND  M0RTAK8. 


29 


of  variation  sliould  be  eliminated  in  all  the  trials,  and  particu- 
larly from  those  which  were  to  furnish  the  data  for  a  direct 
comparison  of  the  qualities  of  the  several  cements,  and  of  mor- 
tars of  diiferent  composition,  but  particularly  those  containing 
large  doses  of  sand.    To  this  end,  all  the  varieties  of  cement 
subjected  to  trial  were  passed  through  a  fine  wire 
sieve,  designated  Ko.  80,  that  is,  containing  eighty   ^ere^sifted  ^in 
fine  wires  to  the  lineal  inch,  each  way,  or  6,.4:00   ^i^®  ^^^^^ 
meshes  to  the  square  inch.   The  sand  used  for  the 
mortars,  when  the  object  was  simply  to  compare  the  qualities 
of  the  several  varieties  of  cementing  substance,  whether  of  pure 
cement,  or  a  mixture  of  cement  and  lime,  though  quite  fine, 
was  clean,  and  tolerably  sharp  and  angular.    It  is  mostly  sili- 
cious,  and  was  obtained  from  a  pit  on  Governor's  Island,  New 
York  harbor,  between  Castle  William  and  Fort  Columbus. 
After  being  passed  through  a  wire  sieve  No.  30,  to  remove 
a  small  per  centage  of  gravel  heterogeneously  distributed 
through  it,  1,000  parts  by  weight  contained : 

1 63  parts  between     and     of  an  inch  in  diameter. 

»        »      -L-   »  -i-  '«  »    "    »      »  Character  of  the 

40      6  0  sand  used. 

352    "        "       ^0  "  "    "     "  " 

183    "  less  than  /o" 


CHARACTER  OF  THE  TESTS  APPLIED  TO  THE  MORTARS. 


30.  1st.  Their  capacity  to  resist  a  transverse  strain,  which 
is  also  a  measure  of  their  tenacity.  To  this  end,  rectangular 
prisms  were  formed  in  a  cast-iron  mould,  under  pressure  or 
otherwise,  as  specially  set  forth  in  each  particular  case.  The 
base  of  these  prisms  was  two  inches  square,  their  height  eight 
inches.  The  first  that  were  prepared  were  formed  in  a  hori- 
zontal mould,  the  pressure  being  applied  to  the  upper  side.  As 
it  was  always  necessary  to  shave  off  one  of  the  sides  of  these 
blocks,  in  order  to  reduce  the  cross-section  to  a  square,  the  ho. 
zontal  mould  was  soon  replaced  by  a  vertical  one,  measuring 


30 


PRACTICAL  TREATISE  ON  LIMES, 


Mortars  made  in  ^  m.  by  2  in.  by  8  in.  in  the  interior,  to  one  end 
prisms  2  in.  by  2        which  the  pressure  was  applied.    "When  the 

•n.  by  8.  and  bro-  ,  , 

ken  on '  supports  prisms  had  attained  the  requisite  age,  they  were 
4  m.  apart.  broken  on^  supports  4  in.  apart,  by  a  pressure 

applied  at  the  middle  point. 

31.  2d.  Their  relative  hardness. — This  was  measured  by  the 
penetration  of  a  steel  point  or  needle,  impelled  by  the  impact 
of  a  falling  body.  The  needle,  which  is  slightly  conical,  or 
tapering  toward  the  point,  is  truncated  at  right  angles  to  the 
axis,  so  as  to  give  a  diameter  at  the  lower  end  of  i^^-  of  an  inch. 
It  protrudes  from  a  socket  in  the  lower  extremity  of  a  vertical 
rod  or  spindle,  to  which  it  is  firmly  secured  by  means  of  a 
Hardness  com-  thumb-screw.  To  the  upper  extremity  of  the 
dfe^^penetrating  spindle  is  attached  a  diagonal  scale  of  steel,  accu- 
by  impact.  rately  graduated  to  tenths,  hundredths,  and  thou- 
sandths of  an  inch,  and  provided  with  a  horizontal  index  firmly 
fixed  to  the  frame-work  of  the  instrument.    The  absolute  pen- 


Fig.  1. . 

etration  of  the  needle  is  obtained  by  taking  the  difierence  be- 
tween the  index  readings  before  and  after  impact.  The  falling 
body  is  a  hollow  metal  cylinder,  weighing  one  pound,  of  which 
the  exterior  diameter  is  about  equal  to  the  length.    This  cylin 


HYDE  AT]  Lie  CEMENTS,  AND  MORTARS. 


31 


der,  in  its  descent,  passes  freely  over  the  spindle,  and  strikes  upon 
a  shoulder  attached  just  above  the  screw.  The  mortar  used 
to  determine  the  hardness  was  that  of  the  broken  prisms,  and 
the  penetrations  were  taken  the  same  day,  generally  but  a  few 
hours  after  they  had  been  broken.  As  these  fragments  were  2 
in.  square  in  cross-section,  and  seldom  less  than  2^  in.  long,  they 
admitted  of  several  trials  with  the  needle.  An  average  of  not 
less  than  four  penetrations,  and  sometimes  more,  at  each  end 
of  the  prisms,  was  taken  on  all  occasions,  except,  when  the  frag- 
ment split  open  at  a  lower  number,  which  was  sometimes  the 
case.    This  instrument  will  be  well  understood  by  referring  to 

32.  3d.  Their  adhesive  properties. — This  was  measured  by 
cementing  bricks  and  blocks  of  stone  together  in  pairs,  and 
afterwards  drawing  them  apart  by  a  force  applied   Adhesiveness  to 
at  right  angles  to  the  plane  of  the  joint.    The  ^ea^^reT''''^ 
bricks  or  stone  of  each  pair  were  arranged  at 
right  angles  to  each  other,  as  seen  in  Fig.  2,  and 
were  kept  together  under  a  pressure  of  500  lbs., 
except  on  occasions  specially  mentioned,  until 
the  mortar  had  set. 

33.  The  device  for  applying  the  pressure  to  the  Tig^ 
prisms^  and  to  the  pairs  of  bricks  or  stone,  while  the  mortar  was 
setting,  is  essentially  the  same  as  that  heretofore  used  for  simi- 
lar purposes.  It  was  also  used  for  testing  the  strength  and  ad- 
hesiveness of  the  mortars,  when  they  had  attained   ^  .  , 

^  Device  for  com- 

the  proper  age.    The  apparatus  consists  essen-  pressing  the 
tially  of  a  bed-piece  and  two  upright  posts,  about  S^mouids,^^ 
one  foot  apart,  connected  by  a  cross-piece  at  the  ^^^^^^^f 

'  ^  prisms,  &c. 

top,  from  the  centre  of  which  is  suspended  a  scale- 
beam,  so  arranged  that  it  can  be  elevated  or  depressed,  as  oc- 
casion may  require,  by  means  of  a  screw.  The  lower  hook  of 
this  beam  is  connected  with  a  horizontal  lever  of  equal  arms, 
so  that  any  weight  indicated  by  the  beam  will  be  transmitted 
without  loss  to  the  reverse  end  of  the  lever,  and  will  then  act 


32 


PRACTICAL  TEEATISE  ON  LIMES, 


as  a  downward  pressure.  The  application  of  this  pressure  to 
the  breaking  of  prisms  is  explained  by  Fig.  3.  It  is  only 
necessary  to  replace  the  wedge-shaped  piece  which  acts  upon 
the  prisms  by  another  which  will  diffuse  the  pressure  over  a 
aorizontal  area  of  greater  or  less  extent — say  about  one  super- 
ficial inch — in  order  to  adjust  the  instrument  for  applying  pres- 
sure to  the  mortar  in  the  moulds,  and  to  the  pairs  of  bricks  or 
stone.    Fig.  4  represents  a  prism  under  pressure.    The  lower 


Fig.  4. 


Fig.  5. 


rig.  3. 

portion  of  the  mould  is  inserted  into  a  mortise  in  the  bed-plate. 
In  order  to  measure  the  force  necessary  to  separate  the  bricks 
or  stones,  they  are  placed  directly  under  the  hooks  of  the  scale- 
beam,  the  lower  lever  having  first  been  removed.  The  lower 
brick  or  stone  is  then  confined  to  the  bed-pieces  by  staples, 
keyed  from  below,  while  the  upper  one  is  embraced  by  the 
ends  of  a  crescent-shaped  iron,  suspended  from  the  hook  of  the 
scale-beam,  as  shown  in  Fig.  5. 

34.  In  all  cases,  the  moment  of  rupture  was  attained  as 
quickly  as  possible — care  being  taken  to  avoid  shocks— by 
Instant  of  ru  pouring  sand  into  the  pan  of  a  spring-balance 
ture  to  be  at-  suspended  from  some  given  point  on  the  beam, 
tained  quickly.         shown  in  Fig.  3.    In  setting  forth  the  results 


HYDEAULIC  CEMENTS,  AND  MORTAES.  33 


of  these  trials  in  a  tabulated  form,  the  actual  breaking  weight 
and  penetration  are,  in  all  cases,  entered  without  reduction 
except  in  the  case  of  separating  the  bricks  and  stone,  when 
an  additional  column  is  inserted  in  some  cases,  giving  the  ad- 
hesive power  per  superficial  inch. 

35.  The  trial  with  the  needle  was  adopted  as  the  most 
ready  means  of  measuring  the  relative  hardness  ^^^^  ^^^^ 

of  the  several  mixtures  containing  no  sand,    with  needle  was 

.  adopted, 
whether  of  pure  cement  or  a  combmation  oi 

cement  with  fat  lime.  Is'othing  further  than  this  was  at  first 
expected  from  it.  M.  Yicat  at  one  time  entertained  the  opin- 
ion, which  he  subsequently  qualified  and  even  abandoned, 
that  "  the  squares  of  the  numbers  which  express  the  penetra- 
tion of  the  rod  are  reciprocally  proportional  to  ^ 

^  .  Law  deduced  by 

the  resistances  to  the  force  which  tends  to  break    Vicat ;  aban- 
the   mortars."    General   Treussart   not  only 
doubts  the  existence  of  this  law,  as  not  fully  established  by 
M.  Yicat's  experiments,  but  advances  objections  to  the  use 
of  the  needle,  which  do  not  appear  to  be  wholly  tenable,  viz : 
1st.  That  it  is  difficult  to  appreciate  exactly 

(jeneral  Xreus- 

its  penetration  ;  sart's  objections 

n  1    m    i.   -i?  'J.  ii' n  •      ^        1         to  the  needle  test, 

2d.  lhat,  II  it  tails  upon  a  gram  of  sand  or 

gravel,  or  even  a  grain  of  lime,  incorrect  conclusions  will  be 

drawn ; 

3d.  That  it  is  applied  to  the  surface  of  the  mortar,  which 
frequently  difi'ers  in  hardness  from  the  interior. 

36.  It  is  submitted  that  the  first  of  these  objections  cannot 
apply  to  an  instrument  like  that  shown  in  Fier.    ^,  ^ 

,  ^  ^      The  first  not  ten- 

1,  if  constructed  with  accuracy  and  used  with    able  when  needle 

.1  T  .  n  i  />  1  is  used  with  care. 

care  ;  the  second  is  equally  without  force  when 

no  sand  is  introduced  into  the  mixtures;  and  even  the  effect  of 

sand  of  fine  grains,  in  large  doses,  might  be  re- 

T    ,  •    n     .  .11  The  second  ditto, 

garded  as  practically  inappreciable,  provided    for  mortars  with- 

the  weight  <5.f  the  falling  body  and  the  distance    ^^^er  ^eavy 

massed  over  in  the  descent  are  such  as  to  cause  impacts. 

3 


34 


PRACTICAL  TREATISE  OK  LIMES, 


deep  penetrations.    Moreover,  an  ordinary  degree  of  precaution 
would  suggest  the  propriety  of  taking  the  average  of  a  h^rge 
number  of  trials  in  preference  to  the  results  indicated  by  a 
single  one,  when  they  can  be  repeated  with  such  ease  and 
rapidity.    It  is  not  contended  that  penetrations  from  impact 
afford  reliable  data  for  comparing  mortars  containing  different 
proportions  of  sand,  or  sand  in  different  degrees  of  fineness. 
The  objection  urged  against  deducing  conclusions  with  regard 
to  the  quality  of  a  mass  of  mortar  from  the  results  of  trials 
restricted  to  its  surface,  is  certainly  worthy  of  consideration 
when  mortars  of  common  lime,  either  with  or  without  sand, 
are  under  trial,  but  is  scarcely  applicable  to  hydraulic  mix- 
Remarks  on        tures.    The   absolute   strength  of  a  mass  of 
third  objection.     mortar  is  not  the  only  good  quality  we  seek. 
Deterioration  from  the  action  of  the  elements  first  takes  place 
upon  the  surface  in  all  cases,  and  it  is  upon  the  surface,  with- 
out regard  to  interior  qualities,  that  the  requisite  power  of 
resistance  against  these  agents  must  be  conferred.  Experience 
teaches  us  that  those  mortars  which  attain  the  greatest  degree 
of  superficial  hardness,  as  shown  by  the  penetrations  of  the 
needle,  absorb  the  least  amount  of  water,  and  are  consequently 
the  least  liable   to   undergo   disintegrations   from  frost  or 
"  weathering."    The  resistance  offered  at  the  surface  to  the 
penetration  of  a  point  acted  upon  by  an  impulsive  force,  there- 
fore, affords  reliable  means  of  judging  of  a  most  important 
property  in  mortars,  even  if  we  admit  that  our  conclusions 
must  necessarily  be  restricted  to  their  surface.    But  this  is  not 
so.    It  is  well  known  that  hydraulic  mixtures  owe  very  little  of 
their  powers  of  sub-aqueous  induration  to  the  absorption  of  car- 
bonic acid  gas,  or  to  superficial  desiccation  ;  that 
harden^ s^ulta^    the  setting  is  not  initiated  at  the  surface,  but 
neousiy  through-  almost  simultaneously  throu2:hout  the  mass  ;  and 

out  the  mass.  .  .  . 

that  the  subsequent  induration  is  not  augment- 
ed, but  rather  retarded,  and  in  some  measure  even  destroyed^ 
by  free  contact  with  the  air,  and  the  absence  of  humidity. 


HYDRAULIC  CEMEJSTTS,  AND  MOETAES.  35 


37.  We  may  safely  assume  that  mortars  of  hydraulic 
cement,  either  with  or  without  sand,  if  submerged,  harden  so 
nearly  homogeneously  throughout  their  entire  thickness,  that 
there  is  no  perceptible  difference  in  hardness  at  the  centre,  and 
at  a  depth  of  -J-^  to  of  an  inch.  At  any  rate,  those  disposed  tc 
entertain  doubts  upon  this  point  can  readily  convince  them- 
selves, by  reference  to  the  tables,  that,  with  individual  excep- 
^    ^       ,      tions,  the  mortars  which  sustain  the  greatest 

The  strongest  '  ^       ^  ^ 

prisms  gave  the  transverse  strain  give  the  smallest  penetrations 
least  penetrations.  n  i«-         ^  •  t  ' 

With  the  needle;  and  it  certainly  is  not  un- 
reasonable to  suppose  that  there  may  exist  a  fixed  law  or  pro- 
portion between  the  resistances  offered  to  two  kinds  of  forces, 
— one  constant,  and  the  other  impulsive, — by  an  inflexible  sub- 
stance like  mortar. 


36 


PEACTICAL  TEEATISE  ON  LIMES, 


CHAPTER  III. 


38.  The  celebrated  Rosend ale  cements, — so  named  from  the 
fact  that  the  stone  was  first  discovered  in  the  township  of 
The  "Rosendale"  I^osendale,  Ulster  County,  I^ew  York,  in  opening 
Cement.  Wj^q  of  ^j^g  Delaware  and  Hudson  Canal — are 

derived  from  the  tentaculate  or  water  limestone  belonging  to 
the  lower  Helderberg  Group,  known  as  Formation  YI.  in  Pro- 
fessor H.  D.  Rogers'  classification  of  the  rocks  of  Pennsylvania. 
As  stated  in  Chapter  I.,  the  deposits  are  mostly  found  within 
Geographical  limits  of  a  narrow  belt  scarcely  one  mile 

limits  of  the  beds  in  width,  skirting  the  northwestern  base  of 

the  Shawangunk  Mountains,  along  the  line  of 
the  Delaware  and  Hudson  Canal,  in  the  valley  of  Rondout 
Creek.  The  beds  are  found  occupying  every  conceivable  in- 
clination to  the  horizon,  being  sometimes  vertical,  seldom  on  a 
level,  and  ordinarily  dipping  at  a  greater  or  less  degree  either 
to  the  northwest  or  to  the  southeast.  The  entire  face  of  the 
country  in  this  region  exhibits  unmistakable  evidences  of  hav- 
ing been  subjected  to  a  succession  of  remarkable  upheavings ; 
some  of  them  have  evidently  taken  place  while  the  limestone 
deposits  were  as  yet  in  a  plastic  form,  by  which  the  strata,  in 
The  beds  are  tor-  niany  localities,  were  twisted  into  a  variety  of 

complex  and  tortuous  shapes,  while  others,  trans- 
piring at  subsequent  periods  more  or  less  remote,  have  ruptured 
the  beds  in  a  variety  of  ways,  frequently  producing  faults,  but 
ordinarily  resulting  in  a  multitude  of  seams  more  or  less  open, 
running  diagonally  across  the  planes  of  stratification.  The 


HTDEAULIC  CEMENTS,  AND  MOETAES.  ^7 


useful  effect  of  these  upheavings  has  been  to  develop,  into 
accessible  and  convenient  positions,  a  vast  amount  of  cement 
stone,  that  would  otherwise  have  been  buried  beyond  the  prac- 
ticable reach  of  ordinary  mechanical  skill. 

39.  The  aggregate  thickness  of  the  several  layers  of  this 
deposit  averages  about  forty-six  feet.  This  includes  several 
strata,  varying  from  four  to  twelve  feet  in  total  thickness, 
which  are  so  changeable  in  character  that  they  ^g^^egate  thick- 
are  fit  for  use  only  in  certain  localities.  The  ness  of  the  sev- 
whole  deposit  is  subdivided  into  several  distinct 

layers,  which  are  widely  dissimilar,  as  a  general  thing,  in  the 
color,  grain,  and  texture  of  the  raw  stone,  and  also  in  their 
hydraulic  properties    after    calcination.     As    Seventeen  layers 
many  as  seventeen  of  these  layers  can  be  traced  ^ 
throughout  the  entire  range  in  Ulster  county. 

40.  ISTo  one  manufacturer  makes  use  of  all  of  these  beds,  and 
no  two  of  them  of  the  same  beds,  in  the  same  Not  all  used  for 
proportions.  This  is  due,  principally,  to  those  the^ changeable** 
marked  variations  in  the  hydraulic  character  of  character  of  stone, 
the  stone,  within  comparatively  short  distances,  which  con- 
stitute a  characteristic  feature  of  this  deposit,  already  referred 
to  in  general  terms. 

41.  In  some  localities,  the  upper  layers  of  the  cement  bear- 
ing series  have  been  removed  by  abrasion,  while    Upper  layers 

in  others,  the  lower  ones  have  been  thrust  so    sometimes  absent, 

^  and  lower  ones 

much  out  of  place  by  the  interposition  of  other    beyond  reach. 

rocks,  or  are  so  far  below  the  general  surface  level,  that  they 

cannot  be  reached  with  facility  or  economy. 

42.  Few  of  the  manufacturers  have  rendered  themselvea 
familiar  with  the  distinctive  and  peculiar  properties  of  the 
several  layers  which  they  introduce  into  their  combination,  in 
stances  being  comparatively  rare  where  they  have  caused  them 
to  be  quarried,  calcined,  and  ground  separately,  even  for  the 
purpose  of  experiment. 

43.  With  few  exceptions,  all  the  stone  taken  from  a  qnarrj 


38 


PEAOTICAL  TEEATISE  ON  LIMES, 


bad,  not  necessa- 
rily objectionable 
in  a  combination. 


2 


enters  into  the  cement  prepared  for  market.  This  includes 
certain  layers,  or  portions  of  layers,  possessing  little  or  no 
Some  inferior  hydraulic  energy  by  themselves,  on  account  of 
stone  IS  used.  i]^q  preponderance  of  inert  silica  or  alumina 
which  they  contain,  and  the  absence  of  homogeneousness  in 
the  composition;  other  portions,  in  which  the  carbonate  of 
lime  is  largely  in  excess,  and  which  may  be  classed  among  ordi- 
nary hydraulic  limes ;  and  still  others,  which  are  an  exagger- 
ated type  of  the  dividing  limes  {chaux  limites)  of  Yicat,  setting 
rapidly  in  water  under  the  most  difficult  circumstances,  suc- 
cedeed  sooner  or  later  by  a  gradual  softening  of  the  whole  mass. 

44.  Although  mortars  giving  rise  to  the  phenomena  last- 
Stone  individually    mentioned  contain  an  excess  of  caustic  lime, 
which  becomes  hydrated  very  sluggishly,  and 
indeed  not  until  the  hydraulic  induration  has 
\  fully    commenced,    and  which, 

therefore,  is  insusceptible  of 
prompt  neutralization  by  the  sil- 
ica, alumina,  and  magnesia  pre- 
sent, in  the  formation  of  those  tre- 
ble hydrosilicates  that  are  prac- 
tically insoluble  in  water,  it  does 
not  necessarily  follow  that  their 
incorporation  in  subordinate  pro- 
portions, and  under  judicious  re- 
strictions, into  the  aggregate  pro- 
duct of  a' quarry,  is  injurious.  In 
certain  cases,  when  care  is  taken  to 
reduce  the  cement  to  a  very  fine 
powder,  with  a  view  to  facilitate  the 
hydration  of  the  lime,  and  to  secure 
a  thorough  incorporation  of  the  sev- 
eral kinds  of  stone  used,  they  are  believed  to  operate  beneficially 
by  furnishing  those  requisite  constituent  ingredients  of  good  ce- 
ment not  found  in  sufficient  quantity  in  the  contiguous  rocks, 


Light  cement 
or 

Upper  Series. 


Middle  Series. 


■*  1 

 6 

«  

> 

Dark  cement 
or 

Lower  Series. 


Fig.  6. 


HYDRAULIC  CEMEJ^TS,  AND  MORTAES.  39 

or  existing  there  in  proportions  capable  of  considerable  in- 
crease, without  producing  an  injurious  excess. 
The  marginal  sketch,  Figure  6,  shows  an  actual  Section  of  the 

p,,         ,  .^T.  T  ^       T      cement  deposits 

section  01  these  deposits,  verined  m  several  locah-  of  Ulster  Co.,  N.Y. 
ties,  where  the  layers  occur  in  regular  order.* 

45.  In  some  localities,  where  the  beds  have  been  upheaved 
into  a  vertical  position,  or  nearly  so,  and  the  stone  of  inferior 
quality  occurs  in  layers  of  sufficient  thickness  to  sustain  them- 
selves, they  are  left  intact,  supported  at  appropriate  intervals 
by  masses  of  the  stone  composing  the  adjacent  layers. 

46.  Some  of  the  most  prominent  features  of  these  several 
layers  will  now  be  briefly  noticed.  They  were  quarried  and 
calcined  separately  by  an  experienced  workman.  For  their 
burning,  "  try -'kilns'''  7  to  7|-  feet  high  and  20  to  24  inches  in  in- 
terior diameter  were  used,  and  the  object  aimed  at  in  each  case 
was  to  submit  every  variety  of  stone  to  that  degree  and  duration 
of  heat  that  would  produce  the  best  results.  Besides  these  tests, 
others  were  made  with  the  stone  by  submitting  it  to  different 
degrees  of  calcination  in  crucibles. 

47.  Nximher  One  is  moderately  fine  grained,  of  a  dark  gray 
color,  and  contains  rather  too  much  silica.  After  burning,  the 
cement  is  of  a  light-drab  color,  and  sets  under  water  in  fifteen 

*  The  sections  of  the  cement  strata  in  Ulster  County,  as  given  in  the  Report  of 
the  State  Geological  Survey,  are  singularly  at  fault.  The  one  purporting  to  have 
been  taken  at  High  Falls,  near  and  just  below  the  bridges  (see  Report  of  First 
District  State  Geological  Survey,  p.  353),  is  as  follows: 

Cement  rock  12tol5  feet  . 

Limestone  10  to  30  " 

Cement  rock   6  to   8  " 

Pyritous  slaty  limestone   4  to  10  " 

Red  shale,  &c  15  to  20  " 

Conglomerate  and  Shawangunk  grits  unknown  thickness. 

The  correct  section  of  the  beds  in  this  locality,  now  constituting  Ogden  &  Co.'s 
quarry,  and  at  the  time  of  the  survey  owned  and  worked  by  Mr.  J.  L.  Hasbrook, 
is  as  follows : — the  layers  above  No.  9  do  not  occur  here. 

Cement  rock  15  to  16  feet. 

Magnesian  limestone,  unsuitable  for  cement,  and 

therefore  not  used.    It  is  dividing  lime   2  to   2|  " 

Cement  rock   5  to   6  " 

Argillaceous  slaty  limestone   -J  to   1  " 

Pyritous  limestone  

Shale,  &c.,  as  before  


40 


PEACTICAL  TREATISE  OlS^  LIMES, 


Number  One  a  minutes  to  bear  the  light  testing- wire.*  This 
Spt^aSwrence-  ^tone,  except  in  the  vicinity  of  Lawrenceville, 
where  it  possesses,  to  a  limited  extent,  the  objec- 
tionable properties  of  intermediate  limes,  furnishes  a  good 
cement  by  itself. 

48.  Nuraber  Two  resembles  the  preceding,  when  in  the  raw 
state,  but  is  of  a  somewhat  darker  color,  and  is  much  quicker 
setting  after  calcination.  In  the  vicinity  of  Lawrenceville  it  pos- 
sesses, to  a  limited  extent,  the  bad  qualities  of  the 

Number  Two  .      '        .  .  ^ 

resembles  Num-   "intermediate"  limes,  and  is  unfit  for  use,  except 

ber  One.  combination  with  the  other  layers.    It  is  not 

excluded  by  any  of  the  manufacturers. 

49.  Numher  Three  is  a  coarse-grained  light-gray  magnesian 
limestone,  containing,  after  calcination,  an  excess  of  caustic 
lime  and  silica  in  the  form  of  sand.  It  belongs  to  the  worst 
Number  Three  ^-^P®  intermediate  limes,  and  is  incapable  of 
ia  an  "  interme-  being  used  alone,  except  after  several  months' 
diate  lime."  i       pt^  ^    •        i        •  .  -^i 

exposure  to  the  enects  oi  air  and  moisture,  either 

in  casks  or  in  bulks,  and  even  then  is  greatly  improved  by  being 
mixed  with  ten  to  fifteen  per  cent,  of  an  active  cement,  with  a 
riew  to  restore  the  energy  destroyed  during  the  process  of  spon- 
taneous slaking.  A  fresh  sample,  mixed  to  a  stiff  paste,  and 
Sets  in  the  air  formed  into  a  cake,  set  in  the  air  in  eight  min- 
ens'when"^^^^^  ^^^^s,  and  was  then  immersed  in  water  at  65°  F. 
water.  soon  began  to  soften,  and  in  one  hour  allowed 

the  light-testing  wire  to  pass  freely  through  it.  Another  cake, 
immersed  in  water  in  the  condition  of  paste,  began  to  set  in 
four  or  five  minutes,  so  far  as  to  lose  the  plastic  form,  which 
was  immediately  followed  by  the  appearance  of  a  multitude  of 
small  cracks,  and  a  rapid  and  progressive  softening  from  the 
surface  inwards.  After  fifteen  minutes  it  was  worked  up  under 
the  trowel,  dried  off  with  blotting-paper  to  a  stiff"  paste,  again 
formed  into  a  cake,  and  immersed.    At  the  expiration  of  twenty 


♦For  a  desci-iption  of  the  testing-wire,  see  paragraph  121. 


HYDEAULIC  CEMENTS,  AND  MOETARS.  41 


minutes,  a  close  network  of  cracks  again  covered  the  surface, 
when  it  was  worked  up,  as  before,  for  the  second  time.  This 
operation  was  repeated  for  the  third  and  fourth  times  before  the 
submerged  cake  would  retain  its  form  under  water,  and  indu- 
rate without  cracking.  It  then  required  six  days  to  bear  the 
aV  inch  wire,  loaded  to  one  pound.  Some  of  the  powdered 
cement  was  heated  to  redness  for  half  an  hour,  in  order  to 
approximate  more  nearly  to  the  condition  of  complete  calcina- 
tion, but  its  qualities  were  in  no  respect  improved  thereby. 
Some  of  the  same  cement,  when  fourteen  months  old,  after 
having  been  preserved  in  an  ordinary  powder-keg,  without 
paper  lining,  during  that  period,  had  entirely  lost  the  dangerous 
property  of  disintegrating  under  water,  which  it  possessed  in 
such  an  eminent  degree  when  fresh.  It  had  also  parted  with 
much  of  its  hydraulic  energy,  requiring  from  eight  to  nine  hours, 
when  submerged,  to  attain  the  requisite  hardness  to  support 
the  light-testing  wire,  and  twenty  hours  to  support  the  heavy 
one.  Some  of  this  old  cement  was  heated  to  redness  for  half 
an  hour,  which,  while  it  fully  restored  its  hydraulic  activity,, 
at  the  same  time  destroyed  its  ability  to  stand  up  under  water. 

Trials  were  also  made  by  adding  to  this  cement  a  soluble 
alkaline  silicate,  in  order  that  silica  might  be    Trials  with  "  solu- 
presented  to  the  lime  in  a  condition  favorable  to  glass." 
an  immediate  combination  with  it,  with  a  view  to  anticipate,  as 
it  were,  the  initial  induration  of  the  native  hydraulic  ingredients. 
The  results  were  entirely  satisfactory.    The  double  silicate  of 
potash  and  soda  was  employed  for  this  purpose,  in  the  succes- 
sive proportions  of  11,  9  and  5i  per  cent.,  by  mixing  it  with  the 
water  used  for  bringing  the  cement  to  the  con-    Eleven  per  cent, 
dition  of  paste.    In  the  first  two  cases  the  sue-  Three 
cess  appeared  to  be  perfect,  and  resulted  in  the    ^  good  cement 
cakes  setting  under  water  in  ten  minutes  to  bear  the  light  test- 
ing-wire, and  in  twenty-five  and  thirty  minutes  respectively  to 
bear  the  heavy  one,  without  any  subsequent  appearance  of 
cracks  or  change  of  form.    With  5^  per  cent,  of  the  alkaline 


42 


PEACTICAL  TEEATISE  OlS^  LIMES, 


silicate,  the  cracks  upon  the  surface  were  not  entirely  avoided, 
but  they  penetrated  but  a  very  little  way  into  the  mortar, 
caused  no  visible  change  of  form,  and  appeared  to  exercise  no 
influence  upon  its  ultimate  strength  and  hardness. 

50.  Nwmher  Four^  in  some  localities,  is  solid  and  compact 
Number  Four  throughout,  and  in  others  is  subdivided  into  two 
subdivided  into  layers  of  nearly  equal  thickness.  The  upper 
two  layers.  portion  is  fine  grained,  dark  blue,  burns  of  a 
light  drab  color,  and  is  quick  setting ;  that  below  is  darker 
after  calcination,  contains  more  lime,  and  does  not  set  readily 
under  water,  if  immersed  in  the  state  of  paste.  Between  these 
two  subordinate  members  of  this  layer,  a  thin  sheet  of  argillo- 
calcareous  slate  sometimes  occurs,  which  has  to  be  excluded 
from  the  combination.    With  this  exception,  the  entire  layer, 

,.   ,        worked  tosrether,  makes  a  cement  of  fair  average 

Tne  entu'e  layer  ^  ?  t> 

makes  good  ce-  quality,  and  there  is  perhaps  no  member  of  the 
deposit  in  Ulster  Co.  which  preserves,  through- 
out its  entire  development,  a  character  more  uniformly  reliable. 
Immersed  in  the  state  of  paste,  in  water  at  65°  F.,  it  hardens 
so  as  to  support  the  light  testing-wire  in  fifteen  to  twenty  min- 
utes, and  the  heavy  one  in  twenty-five  to  thirty  minutes. 

51.  Numher  Five.    This  layer,  throughout  the  entire  range 

of  the  beds  as  yet  opened,  except  in  the  quarries  belonging  to 

the  Newark  Lime  and  Cement  Manufacturing  Company,  at 

the  mouth  of  the  Rondout  Creek,  is  a  coarse-grained  magnesian 

limestone,  containins;  so  larp:e  an  excess  of  car- 
Number  Five        ^  '  .        .       .  m      1  T 
slakes  after  cai-    bonate  01  hme  that  it  generally  slakes  alter  cal- 

meagTe\me%iid  cination,  like  hydraulic  or  meagre  lime.  In  the 
js^g^erally  re-  quarries  of  the  Hudson  River  Company,  about 
five  miles  back  from  the  Hudson,  the  upper  half 
of  the  layer  is  more  highly  charged  with  clay  and  magnesia, 
and  is  so  far  modified  in  its  prevailing  character  that  it  is  in- 
cluded in  the  combination.  "With  these  two  exceptions,  the 
stone  is  rejected  by  manufacturers. 

52.  Number  Six  is  a  limestone  of  slaty  structure,  containing 


HYDEAULIC  CEMENTS,  AND  MORTAES.  43 


a  .arge  amount  of  clay  and  lime,  particularly  of  the  latter,  and 
possessing,  to  a  certain  extent,  the  objectionable  dumber  Six  is  an 
jroperties  of  J^umber  Three.  It  varies  in  thick-  intermediate  lime, 
ness  from  six  inches  to  two  feet,  and  possesses  a  distinct  devel- 
opment in  all  the  quarries,  except  those  at  the  mouth  of  the 
Rondout  Creek,  where  it  has  either  been  omitted  in  the  depo- 
sition, or  has  been  more  or  less  uniforml}^  distributed  through 
out  the  contiguous  layers.  The  latter  would  appear  to  be  the 
most  probable  hypothesis,  as  those  layers.  (Five  and  Seven) 
which  in  most  of  the  quarries  contain  a  ruinous  excess  of  car- 
bonate of  lime,  constitute  in  this  locality  the  best  stone  of  the 
deposit.  "When  made  into  cement,  and  allowed  to  set  in  the 
air,  the  influence  of  water  upon  it  after  immersion  is  moderately 
slow,  so  that  the  mortar  is  not  thrown  down  completely,  like 
that  derived  from  I^umber  Three,  but  is  simply  covered  with 
many  deep  cracks.  A  prism  measuring  2  in.  X  2  in.  X  7  in. 
was  formed  of  a  paste  of  the  pure  cement  from      .  . 

^  -t  rrism  of  pure 

this  layer,  as  developed  at  High  Falls,  and  im-   cement  from 

.       .  .        this  layer. 

mersed  m  water  alter  supporting  m  twenty  min- 
utes the  light  testing-wire  in  the  air.  After  twenty  hours,  it 
began  to  swell  and  crack  along  the  longest  edges, 
the  cracks  being  directed  toward  the  axis.  After 
thirty  hours,  these  cracks  presented  an  exterior 
opening  of  and  after  fifty  hours,  of  J  of  an  inch. 
The  prism  then  broke  into  three  pieces  trans- 
versely, and  was  nearly  a  week  in  assuming  a 
stable  form.  The  form  of  a  cross  section  at  that  time  is  shown 
in  Fig.  Y. 

53.  Number  Seven  is  perhaps  the  most  changeable  member 

of  the  cement  deposit.    ISTear  High  Falls,  on  Coxon  Cove  Creek, 

it  was  manufactured  into  a  cement  several  years  ago  by  Mr. 

0']Sfeill,  which  was  considered  by  the  late  Col. 

J.  L.  Smith,  of  the  Corps  of  Engineers,  superior  aS^oTNumbe^* 

to  any  cement  brought  into  market  at  that  time.  S?!®^;""^^^^ 

_      ^  O'Neill  cement 

In  other  localities,  near  High  Falls,  the  stone  is 


PEACTICAL  TEEATISE  ON  LIMEb, 


in  every  respect  as  good  as  that  used  by  O'l^Teill,  but  all  at- 
tempts to  turn  it  to  any  account  elsewhere  have  failed,  except 
at  a  point  above  one  mile  south  of  Rosendale  Tillage, 
where  it  was  worked  in  1840,  and  at  the  mouth  of  Eondout 
,    „  Creek,  twelve  miles  distant,  where  it  is  of  ffood 

Number  Seven,  ^ 
not  generaUy       quality,  and  furnishes  about  25  per  cent,  of  all 

the  stone  used  in  that  neighborhood.  In  con- 
nection with  the  two  overlying  strata,  Five  and  Six,  it  con- 
stitutes the  middle  rock,  a  prominent  feature,  common  to  all 
parts  of  the  range  (with  the  exceptions  mentioned  above)  which 
is  not  disturbed  in  quarrying.  The  prevailing  character  of 
Is  generally  left  dumber  Seven,  to  which  its  bad  qualities  are 
undisturbed  in      chiefly  due,  is  its  remarkable  and  persistent  want 

the  quarry. 

01  homogeneousness.  When  burnt,  it  presents  an 
entire  absence  of  any  uniformity  of  color,  being  generally  vari- 
egated and  mottled  in  appearance,  exhibiting  almost  every 
grade  of  neutral  tint  between  pure  white,  derived  from 
masses  of  carbonate  of  lime,  and  the  darkest  brown,  approach- 
ing to  black.  Hence  the  constituent  elements  of  the  stone, 
although  they  may  be  present  in  suitable  proportions,  are  be- 
yond the  influence  of  those  mutual  reactions  which  take  place 
dnring  the  calcination,  when  the  ingredients  are  in  intimate 
and  homogeneous  contact,  and  the  lime  which  should  have  en- 
tered into  combination  with  the  silica  remains  free  and  in  ex- 
cess. Instead  of  being  pure,  however,  or  practically  so,  a  con- 
dition which  would  be  favorable  to  its  instantaneous  slaking 
when  brought  into  contact  with  water,  it  is  mixed  with  a  suffi- 
ciency of  foreign  matter  to  render  it  meagre,  technically  so 
called,  and  consequently  sluggish  and  tardy  in  assuming  the 
form  of  hydrate.  ]^ umber  Seven  is  therefore,  with  the  excep- 
tions noted,  an  intermediate  lime,  and  unfit  for  cement. 

54.  Number  Eight  is  unsuitable  for  cement  in  any  part  of 
the  range  yet  opened.  It  is  much  more  uniform  in  appearance, 
Number  Eight  and  is  far  less  heterogeneous  in  composition,  than 
L'cement^^       Number  Seven.    In  the  vicinity  of  High  Falls, 


HYDEATJLIC  CEMENTS,  AND  MOETAES.  45 


it  is  characterized  by  the  objectionable  proper- 
ties of  ISTumber  Three.    It  will  commence  to  set  readily  under 
water,  but  in  a  few  hours  becomes  converted   will  not  set 
into  a  thin  paste.     Further  east,  it  loses  all  underwater 
power  of  indurating  under  water,  and  will  not  retain  in  that 
situation  a  set  taken  in  the  air.     In  some  localities  it  adheres 
to,  or  rather  forms  a  part  of  Number  Seven,  and  is  left  stand- 
ing with  it,  while  the  underlying  and  overlying  strata  are 
removed  ;  in  others  it  becomes  separated  in  blasting,  and  in 
many  cases,  it  is  feared,  finds  its  way  into  the  manufactured 
cement,  and  injures  its  quality. 

55.  The  layers  numbered  from  Nine  to  Sixteen^  inclusive, 
possess  no  striking  individual  characteristics,  ex-   Layers  Number 
cept  in  two  localities.    Taken  together  in  the  doTouS^'' 
proportion  of  their  development  in  the  beds,  strikingly, 
they  furnish  a  cement  of  good  quality.    Its  hydraulic  activity 
is  somewhat  less  than  that  derived  from  a  combination  of  the 
"  Upper  Series"  of  layers  exclusively,  but,  in  ultimate  strength 
and  hardness,  it  will  compare  favorably  with  any  cements  in 
the  country.    The  two  exceptions  are  as  follows,  viz. :  one  at 
High  Falls,  where  Number  Fifteen  is  an  inter- 
mediate lime  like  Number  Three,  while  Num-   at  High  Falls  is 
ber  Sixteen  sets  more  rapidly  under  water  than   Sm?  and  Num! 
any  strata  in  Ulster  Co.;  and  the  other  at  the   ber  SLxteen  very 
mouth  of  Eondout  Creek,  where  the  Lower 

Series"  of  strata  do  not  occur  at  all,  or  are  so  changeable  in 
hydraulic  character,  chemical  composition,  and  lithological 
features,  that  their  geological  identity  is  a  matter  of  some 
doubt. 

56.  Nwnber  Seventeen^  although  difiering  very  materially 
from  Number  Sixteen  after  calcination,  is  mechanically  at- 
tached to  it,  and  has  generally  to  be  taken  out  with  it.  It 
contains  a  very  large  proportion  of  refractory  j^^^^er  Seventeen 
clay,  and  is  in  most  localities,  and  particularly  ^^^t  a  good  stone, 
at  High  Falls,  very  hard,  like  overburnt  bri  cks,  when  cal- 


46 


PEACTICAL  TEEATISE  01^  LIMES, 


cined  in  the  same  kiln  with  the  other  layers.  It  possesses 
little  hydraulic  energy,  and  should  be  excluded  from  the  com- 
bination. As  a  prominent  feature  of  the  entire  deposit,  the 
color  of  the  burnt  stone  is  subject  to  great  changes,  within 
short  distances. 

57.  At  High  Falls,  the  southwestern  terminus  of  the  deposit 
as  now  worked,  where  the  manufactories  of  the  Ogden  Com- 
pany, and  Delafield  &  Baxter  (formerly  Ogden  &  Delafield) 

^  ^  are  located,  all  the  layers,  and  consequently  com- 
at  High  Falls  is  binations  of  them  adopted  for  the  articles  sent 
cf  "es"'r  "as  ^'^  -narket,  are  lighter  colored  after  burning  than 

we  approach  the  in  any  other  locality.  As  we  approach  the  Hud- 
Hudson  Eiver.  .  . 

son  River  the  "Lower  Series"  undergo  a  decided 

and  sudden  change,  so  much  so,  indeed,  that  at  Lawrence  villa, 
only  two  and  a  half  miles  from  High  Falls,  although  they  fur- 
nish but  .60  of  the  combination  used  by  the  Lawrence  Com- 
pany, and  although  one-half  of  the  remainder  is  brought  from 
High  Falls,  and  is  very  light-colored,  the  combination  is  one  of 
the  darkest  of  the  Rosendale  brands.  Between  this  point  and 
the  Hudson,  their  color  remains  dark,  and  that  of  the  "  Upper 
Series"  becomes  moderately  so.  In  point  of  fact,  the  only 
Rosendale  cements  technically  termed  "  Ughf^  are  the  two 
brands  manufactured  at  High  Falls  by  Delafield  &  Baxter,  and 
the  Ogden  Cement  Company. 

58.  The  Newark  Lime  and  Cement  Manufacturing  Com- 
Newark  Lime  ^pany  is  located  on  the  Hudson  River,  at  the 
ZnuStoing  Rondout  Creek.  Its  works  comprise 
Company.— Ca-   seventeen  cylindrical  kilns  of  the  pattern  shown 

pacity  of  their    .  .n    i  • 

works.  m  Figure  12,  and  the  mill  driven  by  steam- 

power,  containing  five  "  crackers"  and  eleven  run  of  stone  of 
two  and  a  half  feet  in  diameter,  and  two  run  of  four  and  a 
half  feet  diameter.  Four  of  the  crackers,  and  five  run  of 
stone,  can  grind  eight  hundred  barrels  of  cement  per  day.  The 
cement  stone  occurs  in  a  continuous  bed  varying  in  thickness 
from  twenty  to  thirty  feet,  and  dipping  to  the  northwest 


HYDRAULIC  CEMENTS,  AIS^D  MORTARS.  47 


from  45°  to  75°.  It  crops  out  along  the  eastern  slope  of  a 
high  hill  or  bluff,  at  an  elevation,  in  places,  of  from  150  to  170 
feet  above  the  level  of  the  Hudson  River.  This  deposit  is 
reached  by  five  horizontal  tunnels,  which  pierce  the  slope  of 
the  hill  near  its  base  at  five  difierent  points,  by  means  of 
which  the  quarried  stone  is  conveyed  to  the  kilns  by  cars. 
There  is  a  marked  difi'erence  in  the  qualities  of  the  stone  in 
these  several  quarries,  as  well  as  among  the  several  layers  of 
the  same  quarry,  and  great  care  is  exercised  in  distributing  the 
aggregate  yield  of  the  entire  deposit  among  the  several  kilns, 
in  order  to  secure  as  great  a  degree  of  uniformity  in  the  quality 
of  the  cement  as  possible. 

69.  None  of  the  Lower  Series  of  cement  strata  (see  para- 
graph 44)  are  used  by  this  company.  The  upper  a  j^q^^j.  genes" 
layers,  from  ^^'umber  One  to  l!^umber  Three  in-  not  used  bj  this 
elusive,  are  in  some  places  too  highly  charged 
with  carbonate  of  lime  to  admit  of  their  entering  into  the 
combination.  No  attempt,  however,  is  made  (and  it  probably 
would  not  be  advisable)  to  exclude  any  layer  entirely,  the  skill 
and  experience  of  the  workmen  being,  in  a  great  measure, 
depended  upon  to  detect  and  throw  out  those  portions  of  the 
stone  which  might  injure  the  quality  of  the  cement.  These 
generally  occur  in  patches,  varying  from  a  few  inches  to  sev- 
eral feet  in  length  and  breadth,  which  are  recognized  by  their 
coarse-grained  or  crystalline  appearance,  or  some  other  charac- 
teristic feature.  With  the  exception  of  these  rejected  portions, 
all  the  layers  from  Number  One  to  Number  Seven,  inclusive, 
enter  into  the  cement  in  the  proportion  of  their  thickness  in 
the  deposit. 

This  company  has  a  branch  at  Newark,  New  Jersey,  to 
which  place  the  stone  is  conveyed  in  the  raw  state. 

60.  The  Lawrence  Cement  Comjpany^  manufacturing  the 
"  Hoffmann"  brand,  have  their  quarries  and  kilns  above  White- 
port,  about  seven  miles  back  from  Rondout.   ^j^e  Lawrence 
Their  mill,  driven  by  steam-power,  is  located  on   <^ement  Company. 


48 


PRACTICAL  TREATISE  ON  LIMES, 


the  left  bank  of  the  Rondont  Creek,  about  two  and  a  half 
miles  from  its  month,  and  below  the  slack  water  of  the  Dela- 
ware and  Hudson  Canal.  They  have  twelve  kilns  of  the  old 
pattern  (Figure  12),  four  run  of  stone  two  and  a  half  feet  in 
diameter,  and  two  crackers. 

Their  combination  comprises  stone  from  three  quarries,  as 
follows  :  the  first,  eighteen  feet  in  thickness,  comprising  the 
layers  fi  )m  Nine  to  Sixteen,  inclusive ;  the  second,  eight  to  ten 
feet  in  thickness,  containing  l^umber  One  to  Four,  inclusive, 
rejecting  Number  Three,  separated  from  the  first  by  the  "Mid- 
dle Rock ;"  and  the  third,  ten  to  eleven  feet  in  thickness,  com- 
prising the  same  strata  as  the  latter  (One  to  Four,  rejecting 
Number  Three). 

After  calcination,  the  stone  is  carried  in  wagons  to  the  mill, 
four  miles  distant,  and  is  then  mixed  together  in  the  proportion 
of 

13|-  per  cent  of  the  first  quarry  (Numbers  Nine  to  Sixteen), 

26f   "     "       "     second  quarry  (Number  One  to  Four,  rejecting  Number  Three). 

60     "     "       "     third  quarry  (  "        "  "  "         "  ). 

61.  The  Wewark  and  Rosendale  Company  have  all  their 
works  at  Whiteport,  six  miles  from  Kondout,  and  about  three 
miles  from  the  point  of  delivery  to  boats  below  the  locks  of 
the  canal.  They  have  fifteen  kilns  of  the  old  pattern  (Figure 
12),  and  one  of  Page's  Patent  (Figures  13  to  18).  Their 
grinding  apparatus  comprises  three  crackers  and  four  run  of 
five  feet  stone,  driven  by  steam,  and  one  cracker 

The  Newark  ,  ,  i    t  .  p 

and  Eosendale  and  three  run  of  lour  and  a  halt  leet  stone, 
Company.  driven  by  water.    Their  quarries  are  in  the  im- 

mediate vicinity  of  those  belonging  to  the  Lawrence  Company, 
noticed  above,  and  they  make  use  of  the  same  kind  of  stone, 
but  combined  in  different  proportions.  They  have,  from  time 
to  time,  derived  their  stone  from  eight  different  openings,  but, 
at  the  present  time,  work  three  principally.  Two  of  these  are 
parallel  to  each  other,  comprising  respectively  the  Upper  and 
the  Lower  Series  of  layers,  separated  by  the  Middle  Kock, 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


49 


which  is  worthless  in  this  locality ;  the  third  furnishes  the 
Upper  strata  only,  One  to  Four,  inclusive.  Their  combination 
is  as  follows : 

50  of  the  Upper  Layers  (One  to  Four)  from  two  quarries,  rejecting  part  of  No.  Three. 
50  of  the  Lower  Layers  (Nine  to  Sixteen). 

62.  The  Rosendale  Cement  Company^  manufacturing  the 

Lawrence"  brand,  is  located  at  LawTenceville,  on  the  line  of 
the  Delaware  and  Hudson  Canal,  six  and  a  half  miles  from 
Rondout.  They  have  seven  kilns  of  the  old  pattern  (Fig.  12), 
and  four  run  of  stone,  four  feet  nine  inches  in 
diameter.  They  grind  by  water  power.  The  ^^^fntCompL,. 
Stone  is  procured  from  three  quarries,  as  follows 

The^r^^  is  near  High  Falls,  two  miles  above  Lawrenceville, 
and  furnishes  the  Upper  Layers  (One  to  Four,  inclusive),  of 
which  a  large  proportion  of  Number  Three  is  rejected.  This 
stone,  after  burning,  is  conveyed  by  land  carriage  to  the  mill 
at  Lawrenceville. 

The  second  quarry  is  situated  on  the  east  side  of  Rondout 
Creek,  at  LawTenceville,  and  furnishes  the  Lower  Layers  (JSTine 
to  Sixteen,  inclusive). 

The  third  is  about  a  quarter  of  a  mile  distant  from  the  latter, 
on  the  west  side  of  the  creek,  and  contains  the  layers  One  to 
Four,  inclusive,  of  which  J^umber  Three  is  rejected.  This  last- 
mentioned  bed  overlies  in  regular  order  the  Middle  and  Lower 
Series.  Numbers  Nine  to  Sixteen  were  formerly  quarried  at 
this  point,  and  included  in  the  combination,  but  for  some  years 
past  have  been  omitted,  on  account  of  the  alleged  presence  of 
an  excess  of  carbonate  of  lime,  an  objection  which  is  presumed 
to  be  more  imaginary  than  real,  as  the  strata,  having  been 
treated  separately  with  great  care,  gave  results  which  com- 
pared favorably  with  those  obtained  from  the  corresponding 
layers  on  the  opposite  side  of  the  creek. 

The  stone  from  each  quarry,  after  being  burned  separately, 
is  added  to  the  combination  in  grinding  in  the  following  pro- 
portions, viz.  : 
4 


\ 


50  PEACTICAL  TREATISE  ON  LIMES, 

.20  of  the  first,  One  to  Four,  inclusive,  rejecting  most  of  No.  Tliree. 

.60     "     second,  Nine  to  Sixteen,  inclusive. 

.20     "    third.  One  to  Four,  inclusive,  rejecting  No.  Three. 

63.  Delafield  &  Baxter^  formerly  Ogden  &  Delafield,  are 
located  at  the  High  Falls  of  Eondout  Creek,  twelve  miles 
Delafield  &  from  its  mouth,  on  the  Delaware  and  Hudson 
Baxter.  Canal.     Their  mill  is  driven   by  water-power, 

and  consists  of  three  crackers,  and  four  run  of  four  and  a  half 
feet  stone.    They  have  six  kihis  of  the  usual  form  (Fig.  12). 

Three  quarries  furnish  the  stone  used  in  the  combination. 
The  first  comprises  the  layers  from  Kine  to  Sixteen,  inclusive, 
of  which  parts  of  Thirteen  and  Fifteen  are  too  highly  charged 
with  carbonate  of  lime,  and  have  to  be  rejected ;  the  second 
comprises  the  Upper  Strata,  One  to  Four,  inclusive,  of  which 
portions  of  JS^umber  Three  are  excluded.  These  two  quarries 
are  located  near  each  other ;  the  third  is  about  half  a  mile 
distant,  and  contains  Number  Sixteen  only,  which  occurs  in  a 
partially  disintegrated  or  slaty  form,  and  is  therefore  known  as 
the  "  Slate  Quarry."  In  the  combination,  the  products  of 
these  three  quarries  are  mixed  together  in  equal  proportions, 
viz. : 

33^  of  Nine  to  Sixteen,  inclusive,  rejecting  portions  of  Thirteen  and  Fifteen. 
33^  of  One  to  Four,  "  "  No.  Three. 

33^  of  No.  Sixteen. 

Layer  l^umber  Sixteen  in  this  locality  possesses  remarkably 
quick  settino^  properties.    It  will  harden  under 

Layer  Number      ^  .  if     i  .  tt, 

Sixteen  very  water  more  rapidly  than  any  cement  in  Ulster 
quick  setting.  County,  and  is  added  to  the  combination  with 
a  view  simply  to  increase  its  hydraulic  activity  and  energy. 
Delafield  &  Baxter  are  also  the  proprietors  of  the  quarry 
w^hich  some  years  ago  furnished  the  O'Neill  cement,  an  article 
which  sustained  a  high  reputation  among  military  engineers. 
It  comprises  the  middle  layers  Six  and  Seven.  It  is  not 
worked  at  the  present  time,  but  will  probably,  at  no  distant 
period,  have  to  replace  their  "Slate  Quarry"  in  the  combina- 
tion, as  the  latter  is  becoming  exhausted. 


HYDRAULIC  CEMENTS,  AND  MORTARS.  51 


64.  The  Ogden  Rosendale  Cement  Company  is  also  lo- 
cated at  High  Falls,  near  Delafield  &  Baxter's.  Their  mill 
is  driven  by  water-power  of  great  capacity,  and  contains  two 
crackers  and  four  run  of  four  and  a  half  feet 

The  Ogden  Ro- 

stone  ;  their  kilns,  at  present  four  in  number,  sendaie  Cement 
are  of  the  old  pattern  (Fig.  12).  The  stone  is  ^°°^P^°y- 
derived  from  an  opening  contiguous  to  Delafield  &  Baxter's 
"  Slate  quarry,"  and  comprises  the  Lower  Series  of  layers  Kine 
to  Sixteen,  inclusive,  rejecting  IS'umber  Fifteen  on  account  of 
the  large  excess  of  carbonate  of  lime  which  it  contains,  and 
which  places  it  among  the  intermediate  limes.  Layers  Mne 
to  Thirteen  are  subject  to  frequent  and  peculiar  variations  in 
hydraulic  energy,  containing  in  places  so  large  an  excess  of 
caustic  lime  after  calcination,  as  to  render  it  necessary  to  reject 
these  portions  when  detected. 

The  combination  adopted  by  this  company  is  varied  from 
time  to  time,  as  circumstances  require,  Number  Sixteen  being 
principally  depended  upon  to  compensate  for  any  deficiency  in 
hydraulic  activity  in  the  superincumbent  layers.  The  usual 
proportion  is : 

50  of  layers  Nine  to  Fourteen,  inclusive,  rejecting  parts  of  Nine  and  Thirteen. 
50  No.  Sixteen. 

The  color  is  light,  like  that  of  Delafield  &  Baxter.  Layer 
Number  Sixteen  of  Ogden's  quarry  appears  to  possess  all  the 
distinct  and  characteristic  properties  of  Delafield  L^yer  Number 
&  Baxter's  "Slate"  quarry,  that  is,  it  has  a  Sixteen, 
slaty  structure,  burns  light  colored,  and  is  remarkably  quick 
setting  under  water.  It  is  a  noticeable  fact,  that,  in  this  par- 
ticular spot,  this  stratum,  although  distant  but  400  or  500 
yards  from  the  other  quarries  in  the  neighborhood,  possesses 
local  properties  so  peculiar,  that  it  would  be  difficult,  in  the 
absence  of  the  most  direct  and  palpable  evidence  of  their  geo- 
logical identity,  to  believe  them  to  be  parts  of  the  same  layer. 
Tt  is  only  at  High  Falls,  and  apparently  within  contracted 
limits  even  there — possibly  not  more  than  two  to  three  hundred 


52 


PEACTICAL  TEEATISE  ON  LIMES, 


yards  in  extent — that  it  possesses  any  superior  hydraulic  ac- 
tivity. As  we  descend  the  valley  of  the  Rondout,  it  burns 
dark  colored,  and  becomes  comparatively  slow  setting. 

65.  At  Bruceville,  half  to  three-quarters  of  a  mile  below 
High  Falls,  Mr.  iV^.  Bruce  manufactures  cement  from  the 
Lower  Layers,  WmQ  to  Sixteen,  inclusive,  to  which  is  added  a 
stratum  about  eighteen  inches  thick,  situated  twelve  feet  below 
I^^umber  Sixteen,  and  separated  from  it  by  a  conformable  bed 
of  argillaceous  shale.  It  is  not  certain  whether  this  stratum 
forms  a  part  of  the  cement  bed  as  described,  or  is  a  separate 
and  independent  deposit,  formed  out  of  its  usual  position  by 
the  local  intervention  of  the  shale.  This  cement  is  light 
colored,  like  Delafield  &  Baxter's.  Mr.  Bruce  also  works 
the  Lower  Layers  at  the  Green  kilns,  five  miles  from  Rondout, 
near  the  line  of  the  Delaware  and  Hudson  Canal. 

66.  Martin  (&  Clearwater  have  their  works  on  the  line  of 
the  Delaware  and  Hudson  Canal,  seven  and  a  half  miles  from 
Rondout.  This  mill,  comprising  four  run  of  four  feet  eight 
inches  stone,  and  the  requisite  number  of  crackers,  is  driven 
Martin  &  steam-power.  They  have  six  kilns  of  the  old 
Clearwater's.  pattern.  (Figure  12).  Their  stone  is  derived  from 
two  parallel  beds  comprising  the  Upper  and  the  Lower  Series 
of  strata  respectively,  separated  by  the  Middle  Rock,  Numbers 
Five,  Six,  and  Seven,  which  is  here  entirely  unfit  for  cement. 
Their  combination  is  as  follows  : 

•50  of  the  layers  One  to  Four,  inclusive ;  rejecting  portions  of  Three  and  Four. 
.50    "        "     Nine  to  Sixteen,  inclusive. 

67.  The  quarries  of  The  Hudson  River  Cement  Company  are 
situated  about  one  and  a  half  miles  from  the  Delaware  and 
Hudson  Canal,  five  miles  from  Rondout.  Their  mill,  compris- 
ing four  run  of  four  and  a  half  feet,  and  two  run  of  two  and  a 
The  Hudson  ^^^^  ^^^^  stone,  as  well  as  their  kilns,  are  in 
River  Company.  Jersey  city.  Their  combination  comprises  equal 
proportions  of  the  stone  from  the  Upper  and  from  the  Lower 
Layers,  including  about  one  half  of  Number  Five,  and  differs 


HYDEAULIC  CEMENTS,  AND  MORTARS. 


53 


from  all  others  into  which  the  Lower  Layers  enter  at  all,  in 
including  the  whole  of  [N'umber  Three.  It  is  therefore  as 
follows : 

-50  of  layers  One  to  Four,  inclusive,  and  one-half  of  Number  Five. 
.50       **       Nine  to  Sixteen,  inclusive. 

68.  Maguire^  Crane  (&  Co.  have  recently  commenced  manu- 
facturing cement  near  Martin  &  Clearwater.  Their  quarries 
join  each  other,  and  are,  in  every  respect,  alike  Maguire,  Crane 
in  the  character  of  the  stone  and  the  number  and  ^ 
thickness  of  the  strata.  Tlieir  mill  is  driven  by  steam-power, 
and  contains  four  run  of  four  and  a .  half  feet  stone.  Four 
cylindrical  kilns  of  the  old  pattern  (Figure  12)  are  used  in 
burning  the  stone. 

69.  The  Lawrenceville  Cement  Manufucturing  Company 
is  located  at  Lawrenceville.  Their  milling  apparatus  com- 
prises six  run  of  four  and  a  half  feet  stone,  four  of  them 
driven  by  steam-power  of  ample  capacity,  and  two  by  water- 
power,  provided  with  the  requisite  number  of  The  Lawrence- 
crackers.    Their  stone  is  derived  principally  from   Y^^^®  Cement 

^  r     J  Manuiactunng 

the  Lower  Series  of  layers.  A  portion  of  JN'um-  Company, 
ber  Seven,  which  is  divided  into  three  layers  possessing  very 
different  qualities,  is  also  added  to  the  combination.  This 
quarry  is  but  two  or  three  hundred  yards  distant  from  the  one 
worked  by  the  Rosendale  Cement  Company,  on  the  west  side 
of  the  Rondout  Creek,  in  which  the  Lower  Layers  have  been 
regarded — with  insufficient  cause,  it  is  thought — as  too  highly 
charged  with  carbonate  of  lime. 

70.  The  Rosendale  and  Kingston  Cement  Company  are 
located  at  Flatbush,  on  the  right  bank  of  the  Hudson  River, 
about  three  miles  above  Rondout.  Their  mill  is  worked  by 
steam-power,  and  contains  four  run  of  four  and  a  half  feet 
stone.  Their  stone  is  burned  in  the  old-fashioned  kilns  (Figure 
12),  and  is  derived  in  part  from  quarries  situated  about  300 
yards  from  the  mill,  which  furnish  the  layers  Three  and  Four 
of  the  Upper  Series,  and  ^N'ine  to  Sixteen,  inclusive,  of  the 


54 


PEACTICAL  TREATISE  ON  LIMES, 


The  Rosendale  I^ower  Series ;  and  in  part  from  an  opeaing  ip 
and  Kingston  Ce-  the  Lower  Layers  on  the  line  of  the  Canal,  neai 

ment  Companj.     -»t      .      d  i        mi  • 

JVLartm  de  Clearwater  s  works,  ihis  stone  is 
transported  in  the  raw  state  to  the  kilns,  which  are  located 
near  the  mill.    Their  combination  is  as  follows  : 

.33^  of  layers  Three  and  Four,  at  Flatbush. 
.33^       "      Nine  to  Sixteen,  inclusive,  at  Flatbush. 
.33^       "  "  from  near  Martin  &  Clearwater's,  ten 

miles  distant. 

71.  Hydraulic  cement  is  manufactured  on  the  Potomac 
River,  which  finds  its  way  to  an  eastern  market,  via  the  Ches- 
apeake and  Ohio  Canal.  There  are  three  works,  located 
respectively  at  Sheplierdstown,  Ya.,  at  Hancock,  Md.,  and  at 
Cumberland,  Md. 

72.  The  Shepherdstown  Works  comprise  two  run  of  four  and 

a  half  French  burr  stones  and  the  necessary  crackers,  driven 

by  water-power,  and  three  perpetual  kilns  of  the  form  given 

in  Figure  11.    Cumberland  coal  is  used  for  burning.  The 

stone  is  derived  from  deposits  which  crop  out  in  several  places 

on  the  banks  of  the  Potomac,  near  the  mill.    Though  consider- 

.  ^  ,  .  ably  tortuous  and  irre2:ular,  their  general  posi- 
Cement  Works  at      ^       ^  .  . 

Shepherdstown,      tion  is  nearly  vertical.    The  stone  is  quarried 

from  the  top  of  the  hill,  is  then  passed  into  the 
kilns,  situated  on  the  slope  below,  and  subsequently  to  flat- 
boats  in  the  mill-race.  These  are  then  floated  into  the  mill,  and 
the  burnt  stone  is  discharged  through  hatchways  up  to  the 
crackers. 

73.  The  deposit  is  in  two  principal  layers,  one  of  which 

furnishes  a  quick^  and  the  other  a  slow  set- 
iayefs%n?gM5°  ting  cement.  The  two  are  mixed  together  in 
and  the  other        nearly  equal  proportions,  a  combination  which 

shw  settmg.  j     i       r    r  ^ 

is  believed  to  yield  a  better  cement  than  either 
of  the  beds  w^ould  if  used  alone. 

74.  Besides  the  quarry  from  which  the  stone  is  at  present 
derived,  there  are  several  outlying  cement  strata,  or  perhaps 


HYDEAULIC  CEMENTS,  AND  MOETAllS.  55 


other  outcrops  of  the  same  strata,  near  bj,  intermixed  with 
layers  of  nearly  pure  limestone,  which  were  added  to  the  com- 
oination  in  former  years ;  but  the  extra  expense  arising  from 
the  necessity  of  quarrying  out  the  common  limestone  in  con 
nection  with  them,  and  the  doubt  as  to  their  possessing  any 
superior  qualities,  led  to  their  final  exclusion. 

It  is  impossible  to  estimate  satisfactorily  the  extent  and 
capacity  of  these  quarries,  and  it  is  believed  that  no  critical 
examination  by  experienced  geologists  has  ever  been  made 
with  that  end  in  view.  The  peculiar  position  of  the  beds  would 
lead  to  the  inference  that  their  development  is  not  only  very 
extensive,  but  practically  available  through  its  entire  extent. 
(See  Table  l^o.  lY.,  paragraph  226,  for  analysis.) 

75.  The  Round  Top  Cement  ^YoT'ks  are  located  about  three 
miles  above  Hancock,  Md.,  on  the  Chesapeake  and  Ohio  Canal. 
The  mill,  which  stands  on  the  tow-path  between  the  Potomac 
River  and  the  canal,  comprises  two  run  of  four  feet  French 
burrs,  driven  by  a  forty-horse  water-power, 

derived  from  the  discharge  of  the  water  of  the  Cem^^t'm)rk8. 
canal  into  the  river.   The  kilns  resemble  those 
at  Shepherdstown  (Figure  11),  and  Cumberland  coal  is  used 
for  burning. 

76.  The  cement  layers  at  this  place  crop  out  on  the  left 
bank  of  the  Potomac,  and  have  been  cut  off  for  the  excavating 
of  the  canal.  They  are  exceedingly  crooked  and  Aggregate  thick- 
tortuous,  bending  up  and  down,  and  doubling  ^^^s  of  deposit, 
upon  each  other  in  a  very  complex  manner.  Their  aggregate 
thickness  is  about  48  to  50  feet,  comprising  eleven  distinct 
layers,  each  possessing  marked  and  peculiar  properties. — 
Commencing  at  the  top  : 

Number  One^  8  feet  thick,  is  highly  argillaceous,  and  is 
very  hard  and  difficult  to  grind  after  calcination.  It  sets 
slowly,  and  will  not  bear  immersion,  unless  first  allowed  to 
set  in  the  air. 

Number  Two,  4  feet  thick,  is  mostly  argillaceous  slate,  and 


56 


PEAOTICAL  TKEATISE  Olf  LIMES, 


is  rejected.  Portions  of  good  cement  stone  are  sometimes 
found  mixed  with  it. 

Number  Three^  one  foot  thick,  is  a  good  cement  when 
properly  treated,  and  hardens  readily  under  water. 

Nuinher  Four^  4  feet  thick,  is  too  calcareous  to  be  used 
Characteristic  cement  alone.     When  suitably  underhurnt 

features  of  the      jt  possesses  a  moderate  decree  of  hydraulic  activi- 

fieveral  layers.  .  ,  ,  i  -,  t 

ty  but  IS  rendered  almost  worthless,  ii  exposed  to 
heat  of  sufficient  intensity  and  duration  to  burn  the  other 
layers  of  the  quarry  properly.    It  is  therefore  rejected. 

Nmiiber  Five,  5  feet  thick,  furnishes  a  remarkably  quick 
cement,  when  the  calcination  is  arrested  at  the  point  of 
complete  expulsion  of  the  carbonic  acid  gas.  Beyond  this 
point  it  will  bear  immersion  in  the  state  of  paste,  but  does  not 
harden  so  quickly  as  when  in  the  condition  of  sub-carbonate. 

Number  Six,  one  foot  thick,  is  nearly  pure  carbonate  of  lime 
and  is  rejected. 

Numher  Seven,  6  feet  thick,  burns  dark  colored,  like  the 
Rosendale  cements,  but  is  not  a  quick  cement  by  itself.  It  is 
used  in  the  combination. 

Numher  Fight,  4  feet  thick,  resembles  Seven,  though 
superior  to  it. 

Numher  Nine,  5  feet,  contains  an  excess  of  carbonate  of 
lime,  and  is,  in  fact,  an  energetic  hydraulic  lime.  It  is  used  in 
the  combination. 

Number  Ten,  one  and  a  half  feet  thick,  is  a  slate.  Rejected. 

Number  Eleven,  11  feet  thick,  gives  a  quick  and  energetic 
cement,  which  hardens  readily  under  water.  It  is  depended 
upon,  in  a  measure,  to  confer  hydraulic  activity  on  the 
combination,  whenever  from  bad  burning,  carelessness  in 
assorting  the  stone,  or  any  other  cause,  there  is  deficiency  in 
this  particular. 

With  the  partial  exception  last  mentioned,  the  layers  that 
are  used  are  combined  together  in  the  proportion  of  their 
developed  thickness  in  the  quarry. 


HTDEAULIO  CEMENTS,  AND  MOETAES. 


51 


The  Round  Top  quarries  contain  a  very  large  amount  of 
cement  stone,  so  situated,  on  the  slope  of  the  river  and  canal, 
as  to  secure  to  the  manufacturer  every  advantage  which  position 
can  afford.    (See  Table  lY.,  paragraph  226,  for  analysis.) 

77.  The  CuinbeTland  Cement  WorTts  are  located  at  Cum- 
berland City,  Md,,  and  comprise  two  run  of  French  burrs,  4|-  and 
5  feet  in  diameter,  respectively,  driven  by  a  35- 

,  •  rri  •  •'•11  Cumberland 

norse-power  engme.    Ihis  power  is  considered   cement  Works, 
sufficient  to  drive  three  run  of  stone.  Three 
kilns,  burning  Cumberland  coal,  and  resembling  those  used  in 
Ulster  Co.,  I^.  Y.,  are  in  operation. 

78.  The  cement  stone  is  derived  from  two  quarries,  situated 
in  close  proximity  to  each  other,  on  Will's  Creek,  near  its 
junction  with  the  Potomac.  The  principal  bed  is  from  35  to 
40  feet  thick,  of  which  the  lower  half  furnishes  a  slow  cement, 
that  will  not  indurate  under  water  unless  first  allowed  to  set 
in  the  air,  and,  even  then,  rather  slowly.  The  upper  half 
yields  a  cement  that  will  bear  immersion  in  the  state  of  paste. 
Each  of  these  two  layers  furnishes  one-third  of  the  combination, 
the  remainder  being  derived  from  a  nine-feet  ledge  a  few 
yards  distant,  which  is  quarried  by  tunnelling.  It  is  quick- 
setting.  Below  this  there  are  other  layers  of  good  cement, 
which  are  not  at  present  used  on  account  of  the  extra  expense 
of  quarrying,  and  one  or  two  thin  beds  of  argillo-magnesian 
limestone,  possessing  the  properties  of  intermediate  limes.  For 
analysis  of  Cumberland  cement,  see  Table  lY.,  paragraph  226. 

79.  The  James  River  Cement  Works  are  located  at  Balcony 
Falls,  Rockbridge  county,  Ya.,  on  the  James  River,  and  the 
James  River  and  Kanawha  Canal.  The  mill  stands  on  the 
tow-path,  and  contains  two  crackers  and  four  run  of  French 
burr-stones  of  medium  size,  driven  by  water-power  derived  from 
a  dam  across  James  River,  erected  by  the  Canal  Company. 
The  power  is  deemed  sufficient  to  turn  six  run 

of  stone.    Six  kilns,  as  represented  in  Figure  cemenrworks. 
11,  are  located  at  the  mills     The  quarries,  of 


58 


PRACTICAL  TREATISE  ON  LIMES, 


which  there  are  two  opened  in  the  same  stratum,  jire  on  the  mar- 
gin of  the  river,  about  one  mile  above  the  mill,  from  which 
point  the  stone  is  transported  to  the  kilns  in  boats,  on  the  slack 
water  of  the  dam.  This  deposit  is  generally  known  in  Yirginia 
as  the  "  Blue  Ridge  quarry."  The  writer  visited  these  rocks 
in  the  summer  of  1858,  under  orders  from  the  Engineer  Bureau 
of  the  War  Department.  The  following  is  an  extract  from  his 
report,  rendered  on  the  31st  of  July  of  that  year  : 

The  cement  vein  or  stratum  is  twelve  to  thirteen  feet  thick, 
and  dips  to  the  northwest  fifty-five  degrees  (55°).  It  crops 
out  on  the  summit  of  an  undulating  table-land,  or,  perhaps, 
more  properly,  a  ridge  situated  at  the  base  of  the  mountain. 

The  direction  of  the  outcrop  is  nearly  north- 
rorentd^e^ol  ^ast  and  southwest.  The  upper  ridge  of  the 
stratum  changes  its  character  very  materially 
before  it  reaches  the  surface,  gradually  disappearing  in  a  soft, 
porous  yellow  stone,  which  in  turn  runs  into  a  hard  clay,  of 
various  shades  of  yellow  and  light  orange,  and  in  various 
stages  of  decomposition.  This  becomes  perceptibly  softer  as 
it  approaches  the  surface  ;  the  upper  portion,  to  the  depth  of 
several  feet,  yielding  readily  to  the  pick  and  shovel.  The 
entire  bed  is  subdivided  into  layers,  varying  in  thickness  from 

one  and  a  half  to  four  feet."  "The  color  of 

the  raw  stone  is  dark  blue,  its  texture  compact,  grain  moder- 
ately fine,  and  fracture  slightly  conchoidal."  For  the  analy- 
sis, see  Table  lY.,  paragraph  226.  The  James  Eiver  Works, 
driven  to  their  full  capacity,  will  turn  off  350  to  400  barrels  of 
cement  daily.  It  is  sent  to  the  eastern  markets  via  the  James 
River  and  Kanawha  Canal,  and  James  River. 

80.  At  Utica^  Lasalle  county,  Illinois,  cement  is  manufac- 
tured from  a  bed  of  stone  seven  feet  thick,  which  crops  out  on 
the  margin  of  Illinois  River,  just  above  the  level  of  high  water. 
.  .  TT^-        It  is  burnt  with  bituminous  coals  in  intermittent 

Cement  at  Utica, 

Lasalle  county,       kilns  of  about  200  barrels  capacity.  It  is  stated 
by  one  of  the  manufacturers  that  perpetual  kilns 


HYDRAULIC  CEMENTS,  AND  MOETAES.  59 


would  not  discharge  the  burnt  stone  readily,  on  account 
of  the  thin  slaty  fragments  into  which  it  splits  in  quarrying. 
Two  parties  are  engaged  in  its  manufacture.  One  of  them  has 
eight  kilns  and  three  run  of  stone  (two  of  four  feet  and  one  of 
four  and  a  half  feet  diameter) ;  the  other  has  three  kilns  and 
one  run  of  four  feet  stone.  Steam-power  is  used  for  grinding. 
The  full  capacity  of  both  works  is  stated  at  700  to  800  barrels 
per  day.   (For  analysis,  see  Table  lY.,  paragi-aph  226.) 

81.  The  SandusTcy  Cement  Works  are  in  Yan  Kensselaer  town- 
ship, Ottawa  county,  Ohio,  on  the  point  of  the  peninsula  oppo- 
site Put-in-Bay  Island,  and  near  Hat  Island.  The  thickness  of 
the  cement  deposit  is  not  accurately  known.  It  is  nearly  hori- 
zontal, and  is  quarried  in  three  or  four  places  to  a  depth  vary- 
ing from  five  to  eight  feet,  down  to  the  level  of 

the  water  of  Lake  Erie.  The  stone  is  burnt  cemtnfwofm 
in  perpetual  kilns  with  coal,  either  bituminous 
or  anthracite,  in  a  manner  similar  in  every  respect  to  that  pur- 
sued in  Ulster  county,  New  York.  The  mill  is  driven  by 
steam-power,  and  comprises  four  run  of  French  burrs  with  the 
requisite  number  of  crackers,  and  is  capable  of  grinding  300 
barrels  per  day.    (See  Table  lY.,  paragraph  226,  for  analysis.) 

82.  I^ear  Louisville^  Kentucky^  at  the  foot  of  the  falls  of  the 
Ohio  River,  there  is  a  deposit  of  cement  stone,  which  for 
many  years  has  beei;i  extensively  used  throughout  the  West, 
and  particularly  along  the  Mississippi  River. 

The  deposit  is  six  feet  thick  j  the  stone  is  burnt    Louisville,  Ky. 
in  the  ordinary  draw-kilns  (Figure  12),  anthra- 
cite coal  being  used  for  fuel.    The  mill  contains  one  pair  of  four 
and  a  half  feet  French  burrs,  driven  by  water-power. 

As  early  as  the  year  1848,  Col.  Long,  of  the  Corps  of  Topo- 
graphical Engineers,  who  had  witnessed  the  successful  appli- 
cation of  the  Louisville  cement  to  building  purposes  in  the 
West,  entertained  a  very  high  opinion  of  its  Long's 

quality,  and  pronounced  it,  when  used  "  in  the    opinion  of  the 

,  Louisville  cement 

formation  of  subterraneous  and  submarine  foun- 


60 


PEACTICAL  TEEATISE  ON  LIMES, 


dations,  and  other  structures  in  similar  situations,  a  cement 
unsurpassed  by  any  materials  of  the  kind  hitherto  employed  for 
such  purposes  in  this  or  any  other  country."  * 

*  The  cost  of  manufacturing  cement  varies,  of  course,  among  the  different 
works,  according  to  local  circumstances,  such  as  the  kind  of  motive  power  used 
for  milling,  the  proximity  of  the  kilns  to  the  quarries  and  to  the  mill,  the  dip  of 
the  strata,  and  the  proportion  of  quarried  stone  not  suitable  for  use,  the  character 
of  the  burnt  stone  with  respect  to  hardness,  &c.,  &c. 

The  Rosendale  cements,  on  account  of  the  superior  facilities,  and  the  brisk  com- 
petition among  the  manufacturers,  are  produced  at  less  expense  than  any  in  the 
country.  Great  pains  have  been  taken  to  obtain  data  for  a  correct  estimate  of  this 
expense. 

The  following  table  is  based  upon  a  work  whose  estimated  capacity  is  300  bar- 
rels per  day,  on  the  supposition  that  the  kilns  and  mills  are  in  such  proximity  that 
the  transportation  of  the  raw  stone  to  the  kilns,  and  of  the  manufactured  product 
to  the  canal,  can  all  be  accomplished  with  five  single  teams.  In  some  works  it  is 
considerably  below  this  estimate. 

CURRENT  ANNUAL  EXPENSES  OF  A  CEMENT  MANUFACTORY  OF  300  BARRELS  DAILY 
CAPACITY,  WORKING  200  DAYS  IN  THE  YEAR: 

Salary  of  Superintendent  $  800  00 

"       "     1  Engineer   500.00 

"      "    1  Fireman  $1.00  for  200  days   200.00 

"       "     1  Smith                        1.25  "     "     "    250.00 

"      "  13  Quarrymen                1.00  "     "     "    2,600.00 

"      "    5  Single  Teams             1.75  "     "     "    1,750.00 

"       "    1  Head  Burner              2.00  "     "     "    400.00 

«      "    3  Assistant  Burners . .  1.00  "     "     "    600-00 

"       "    4  Drawers                    1 00   '*     "     "     800.00 

"      "    1  Miller                       1.75  "     "     »    350.00 

"      "    1  Assistant  Miller  1.25  "     "     "    250.00 

»      "    5  Packers                    1.00  "     "     "    1,000.00 

Powder  for  blasting  14,049  Tons  of  Stone   1,200.00 

Coal  for  burning          "       "          "    2,700.00 

Coal  for  engine,  $1.00  per  day,  200  days   800.00 

Paper  and  nails  for  packing,  I^g.  per  barrel   900.00 


Total  Expenditure   $15,100.00 

Add  15  per  cent,  for  incidental  and  contingent  expenses,  accidents, 

delays,  wear  and  tear   2,235.00 

Annual  consumption  of  quarry,  based  on  total  consumption  in  12 

years   1,000.00 

Interest  on  capital  invested,  $30,000  at  7  per  cent   2,100.00 

Insurance  on  building  and  machinery,  $18,000  at  2  per  cent   360.00 

60,000  new  barrels  delivered  at  the  works,  at  28c   16,800.00 

Total  cost  of  60,000  bbls.  of  cement,  ready  for  delivery  at  the  work.  $37,595.00 
Cost  per  barrel  at  the  work,  ready  for  delivery   62-]% 


HYDEAULIC  CEMENTS,  AND  MORTARS.  61 


83.  At  Kensington^  Conn.^  a  cement  has  been  manufactured 
for  many  years,  which  has  never  found  a  distant  market  in 
large  quantities,  owing  to  the  expensive  land  transportation  to 
which  it  would  be  subjected,  and  which  pre- 
cludes its  ever  coming  in  competition  with  the  Kenskigton  Conn. 
Kosendale  cements,  for  general  use.  A  marked 
superiority  for  stucco-work  in  exposed  positions  is  claimed  for 
it  by  the  proprietors,  on  the  authority  of  the  late  A.  J.  Down- 
ing, Esq.,  who  gave  it  a  preference  over  all  others  for  that  par- 
ticular purpose.  The  mill  is  driven  by  water-power,  and  con- 
tains two  run  of  four  feet  Esopus  Stone  (Shawangunk  grit). 
The  deposit  of  cement  stone  is  about  three  miles  from  the  mill. 
Its  thickness  varies  from  one  to  eight  feet. 

84.  Cement  manufactories  also  exist  at  Akron,  Erie  county, 
^^ew  York,  at  Lockport  and  Fayetteville,  New  York,  and  at 
other  points  on  the  line  of  the  Erie  Canal. 

The  cements  from  Manlius  and  Chittenango,  tori^s^at  Ak^ou  °* 
New  York,  rank  in  point  of  hydraulic  activity  ^^^j^J^^!;^^^^^^  Y 
between  the  genuine  cements  and  the  eminently 
hydraulic  limes,  some  portions  of  the  quarries  partaking  largely 
of  the  character  of  intermediate  limes.  These  two  last-named 
cements  require  to  be  used  with  great  care. 

85.  Besides  the  foregoing  cements,  two  well-known  imported 
varieties  have  been  introduced  to  a  limited  extent  into  these 
trials,  viz. :  the  artificial  Portland  cement  of  England,  and 
Parker's  Koman  cement.  As  these  cements  are  both  exten- 
sively used  in  Europe,  and  have  been  submit- 
ted to  a  great  many  trials,  their  character  and  PorTiandcementa 
value  are  well  known  among  those  who  have 

given  the  subject  attention.  They  therefore  furnish  us  the 
means  of  comparing  mortars  made  from  our  products  with 
those  in  common  use  throughout  Europe.  In  Europe,  all 
natural  cements  are  generally  denominated  Poman  cements, 
to  distinguish  them  from  Portland  cements,  which  are  artificial 
combinations  of  limestone  (usually  chalk)  and  clay. 


62 


PEACTICAL  TEEATISE  ON  LIMES, 


KOMAN  CEMENT. 

86.  Tins  cement  is  manufactured  in  both  England  and  France^ 
by  a  process  essentially  similar  to  that  pursued  in  making  ce- 
ent  in  this  country.    It  is  derived  from  argillo-calcareous,  kid- 
ney-shaped stones  called  "  Septaria,"  belonging 

Source  of  Roman     to  the  Kimmerido-e  and  London  clay,  g-enerally 

cement.  ^  j  '  »  ./ 

gathered  on  the  sea-shore  after  storms  and  high 
tides,  though  sometimes  obtained  by  digging.  The  manufac- 
tured article  usually  takes  its  name  from  the  locality  which 
furnishes  the  stone,  as  "  Boulogne"  Roman  cement,  "  Har- 
wich" or  Sheppy"  Roman  cement.  The  several  brands  pos- 
sess almost  identically  the  same  composition.  (  See  Table  lY., 
paragraph  226.) 

NATURAL  PORTLAND  CEMENT. 

87.  A  cement  is  manufactured  by  MM.  Demarle  &  Co.,  of 
Boulogne-sur-mer,  from  one  of  the  layers  of  the  Kimmeridge 

clay,  situated  about  160  feet  below  the  strata 

Natural  "  Port- 

land"  cement  of  in  which  the  "  Boulogne  pebbles"  or  "  Septaria" 
Boulogne-sur-mer.   ^^.^  ^^^^^^^    rpj^^   ^^p^^-^  is  argillo-calcareous, 

and  is  burned  and  ground  up  for  cement  in  its  natural  state 
without  the  addition  of  lime,  furnishing  the  so-called  Natural 
"  Portland"  cement.  It  was  exhibited  in  Paris  at  the  Palais 
de  rindustrie,  in  1855,  and  a  report  thereon  by  M.  Delesse, 
Engineer  of  Mines,  sent  to  me  by  the  manufacturers,  has  sup- 
plied the  following  particulars  : 

No  locality,  except  Boulogne,  is  known  to  furnish  a  soft  de- 
posit that  can  be  excavated  with  pick  and  shovel,  possessing 
in  suitable  proportions  all  the  ingredients  of  good  cement.  The 
calcareous  clay  which  is  used  in  making  "  Port- 
infTrior  CrSa-^  land"  cement  is  found  in  the  Inferior  Cretaceous 
ceousFormation.  p^r^nation.  Its  paste  is  nearly  homogeneous,  and 
Percentage  of  contains  from  nineteen  to  twenty-five  per  cent, 
clay  contained.         ^^^^     rj.^^^  proportions  of  silica  and  alumina 


HYDEAULIO  CEMENTS,  AND  MORTAES. 


63 


contained  in  the  latter  may  vary,  v^ithout  any  inconveniences 
resulting  therefrom  ;  but  it  is  important  to  avoid  sand,  as  far 
as  possible.  Accordingly,  those  portions  containing  more  than 
one-twentieth  of  sand  are  rejected. 

88.  It  is  known,  that  in  order  to  obtain  artificial  "Portland'' 
cement,  it  is  by  no  means  necessary  to  use  exclusively  the  ar- 
gillaceous mud  deposited  by  certain  rivers :  the  limestone 
may  be  mixed  with  either  marls  or  clays,  the  only  necessary 
condition  being  to  secure  a  perfectly  homogeneous  mixture  of 
carbonate  of  lime  and  clay,  in  the  above-mentioned  propor- 
tions. It  is,  moreover,  indispensable  that  the  mixture  should 
be  quite  intimate,  otherwise,  even  with  the  required  propor- 
tions, it  may  fail  to  yield  good  "  Portland"  cement.  For  this 
reason,  M.  Dupont,  the  patentee,  has  adopted  for  grinding  the 

original  materials  for  the  natural  "Portland" 

,      .  .    .  Mills  for  grinding 

cement,  horizontal  mill-stones,  similar  to  those   the  calcareous 

used  for  sjrindins:  corn.     Instead  of  using  a 

great  quantity  of  water,  in  order  to  separate  the  materials  by 

levigation,  as  is  practised  in  the  English  process,  he  adds  only 

enough  to  form  a  plastic  paste.    Immediately  after  this  paste 

has  passed  under  the  mill,  it  is  shaped  into  small  bricks, 

which  are  placed  in  the  kiln  as  soon  as  they  are  properly 

dried.    As  above  intimated,  a  most  essential  condition  of  the 

paste  is  that  its  composition  should  be  quite  homogeneous, 

otherwise  the  portions  richest  in  silica  would  fuse  and  form 

a  silicate,  which  could  not  enter  into  combination  with  water. 

89.  During  the  calcination,  it  is  of  the  utmost  importance 
to  have  the  temperature  sufficiently  elevated.  The  ordinary 
temperature  of  lime-kilns  would  be  far  too  low, 

for  that  would  merely  drive  off  the  water  and    a  high  heat, 

carbonic  acid.    The  materials  must  receive  a    producing  incipi- 
ent vitrincation. 

white  heat,  whereby  they  can  become  slightly 

agglutinated.    The  state  of  incipient  vitrification  appears  to 

be  the  proper  limit  of  calcination. 

90.  Moreover,  a  high  heat,  however  intense,  is  not  ob- 


64 


PRACTICAL  TREATISE  ON  LIMES, 


jectioiiable,  as  only  those  portioDs  that  would  have  injured 
the  quality  of  the  cement  will  become  completely  fused.  This 
fusion  will  then  afford  the  means  of  separating  and  excluding 
those  parts  which  do  not  possess  the  proper  composition,  and 
are  unfit  for  use. 

Assorting  the  After  the  calcination,  a  selection  is  neces- 

burnt  clay.  g^^^  .  ^j^^  pulverulent  and  scorified  portions  of 

the  mass  are  picked  out  and  thrown  away. 

92.  Properties. — When  taken  out  of  the  kiln,  it  is  in  the 
shape  of  fragments  warped  and  cracked  by  contraction,  and 
of  a  gray  and  sliglitly  greenish  color.  Its  powder  has  a  some- 
what paler  shade.    The  weiglit  of  one  cubic  metre  of  loose 

powder  is  1,270  kilograms  (2,136  pounds  to  the 
Siogne^ '^^ Port-  cLibic  yard),  which  will  sometimes  reach  1,385 
X?:" with  kilograms  (2,329  pounds  per  cubic  yard).  The 
that  of  artificial      Boulogne  "  Portland"  cement,  therefore,  has  a 

"Portland."  ^  .  .  i     -r^     -,.  -,  -r. 

greater  specific  gravity  than  the  English  "  Port- 
land," as  that  from  ^Newcastle  weighs  only  916  kilograms  to  the 
cubic  metre,  and  that  from  London  1,057  kilograms  (1,541  and 
1,778  pounds  per  cubic  yard,  respectively).  During  the 
mixing  with  water  in  forming  paste,  the  Boulogne  "  Portland" 
undergoes  a  diminution  in  volume  of  .3,  the  same  as  the  Bou- 
logne "Boman"  made  from  "  Septaria."  The  volume  of  water 
which  combines  with  it  in  mixing  is  .366,  according  to  M. 
Dupont.     In  weight,  1.00  of  "  Portland"  cement,  therefore, 

absorbs  .29  of  water,  which  shows  that,  for  an 
The  Boulogne        .  i     t-»     i  t~»     i  m 

"Portland"  ab-      equal  weight,  the  Boulogne  "  Portland  cement 

thanVrBouTogne    i-^quires  far  less  water  than   the  Boulogne 
"Roman."  It  is    "  Roman"  cement.    This  difierence  is  doubt- 
slower  setting.        -       ^  11.1  1  '  1  ^ 
less  due  to  the  high  temperature  at  which  the 

"  Portland"  cement  is  burnt.  The  same  cause  also  explains 
its  slow  setting,  which  does  not  take  place  until  after  twelve,  or 
even  eighteen  hours. 

93.  This  property  of  setting  slowly  may  be  an  obstacle  to  the 
use  of  the  Boulogne  "Portland"  cement  for  hydraulic  works 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


65 


which  have  to  contend  against  immediate  causes    Slow-setting  oe- 

.  ments  objection- 

01  destruction,  as,  for  instance,  sea  construe-    able,  under  some 
tions  which  have  to  be  executed  under  water  ^^^^cumstances. 
between  tides.    It  is,  however,  possible,  in  the  last-mentioned 
case,  to  obviate  this  inconvenience  by  temporarily  covering 
the  *' Portland"  with  a  quick-setting  cement. 

"  Moreover,  a  quick-setting  cement  is  always  difficult  to  be 
used ;  it  often  requires  special  workmen,  and,  at  Advantageous  im- 
all  events,  a  very  active  supervision.  A  slow-  others, 
setting  cement,  like  the  natural  "Portland" of  Boulogne,  pos- 
sesses the  great  advantage  of  being  manageable  by  ordinary 
masons,  and  can  be  mixed  up  with  additional  water  after 
twelve,  or  even  twenty-four  hours. 

94.  M.  Delesse,  in  the  report  which  furnished  the  foregoing 
details,  remarks :  "  We  have  made,  in  the  laboratory,  some 
gangs  with  Boulogne  'Portland'  cement.  The  sample  upon 
which  we  operated,  and  the  composition  of  which  we  give  be- 
low, was  in  fragments,  and  the  gangs  were  made  directly  after 
the  cement  had  been  ground.  After  a  few  days,  they  displayed 
cracks  showing  contraction.  As  the  cement  exhibited  at  the 
Palais  de  I'Industrie  showed  no  cracks,  these  were  probably  due 
to  the  fact  that  the  cement  experimented  upon  was  fresh  from 
the  kiln,  whereas  ground  cement,  after  being  stored  for  some 
time,  becomes  more  or  less  hydrated,  and  is  less  liable  to  con- 
traction. We  observed,  moreover,  that  the  water  in  which  the 
gangs  were  immersed  was  impregnated  with  a  considerable 
quantity  of  lime.  In  the  natural  '  Portland'  the  lime  is  there- 
fore in  excess,  and  the  whole  of  it  does  not  enter  into  combi- 
nation to  form  hydrosilicate. 

95.  "The  composition  of  the  natural  Boulogne  *  Portland' 
cement  is  as  follows  : 

"Lime   65.13 

Magnesia  58  Analysis  of  the  nat- 

Silica    20.42  ural  Boulogne  "Port- 
Alumina  and  small  quantity  of  oxide  )     -lo  oh  land"  cement. 

of  iron  f  ^^-^^ 

Sulphate  of  lime   a  trace." 

5 


66 


PRACTICAL  TREATISE  ON  LIMES, 


In  analyzing  the  same  cement,  M.  Yicat  found  only  61.75 
of  lime.  This  composition  comes  very  near  that  of  the  Eng- 
lish artificial  "  Portland,"  which  is  given  in  paragraph  131. 
They  are  both  classed  among  the  intermediate  limes  of  Vicat. 
The  calcination  of  these  cements,  at  a  temperature  producing 
vitrification,  develops  a  peculiar  state  of  combination  of  the 
ingredients,  which  confers  upon  them  their  remarkable  proper- 
ties. 


HYDRAULIC  CEMENTS,  AND  MORTAES.  67 


CHAPTEE  lY. 


96.  The  calcination  of  statuary  marble,  or  any  other  pnre 
variety  of  limestone,  produces  quicklime,  by  expelling  from 
the  carbonate  of  lime  (CaO.OOg),  of  which  they     Lime  a  metallic 

.  oxide,  and  how 

are  essentially  composed,  the  carbonic  acid  gas,  produced. 

(CO2),  water  of  crystallization,  and  organic  coloring  matter. 

Lime  is  therefore  a  j)rotoxide  of  calcium,  or,  in  other  words,  a 

metallic  oxide,  the  base,  calcium,  having  been  classed,  since  Sir 

H.  Davy  succeeded  in  effecting  the  decomposition  of  lime^ 

among  the  metals.    Pure  lime  (CaO)  has  a  specific  gravity  of 

2.3,  is  amorphous,  somewhat  sponffy,  hierhlv 

'   .         .      .  ^  '    ,  I  J  Its  characteristics, 

caustic,  quite  infusible,  possesses  great  avidity 

for  water,  and,  if  brought  in  contact  with  it,  will  rapidly  absorb 

.22  to  .23  of  its  weight,  passing  into  the  condition  of  hydrate 

of  lime,  a  chemical  compound,  of  which  the  formula  is 

CaO.HO.     The  reactions  resulting  from  this    Phenomena  de- 

,  .      .  T   T      .  1  .  11     veloped  in 

combination  are  attended  with  certain  marked  "slaking." 

phenomena,  such  as  a  great  elevation  of  temperature,  the 

bursting  of  the  lime  into  pieces  with  a  hissing  and  craclcling 

noise,  the  evolution  of  a  hot  and  slightly  caustic  vapor,  and 

finally,  after  a  few  minutes,  its  reduction  into  an  impalpable 

powder,  of  which  the  volume  is  about  three  and  a  half  times 

that  of  the  original  lime.    In  this  condition  the  lime  is  said  to 

be  slaked. 

97.  Water  dissolves,  according  to  Sir  H.  Davy,  about  one 
four-hundredth  of  its  weight  of  lime,  or,  according  to  Thomson, 


68 


PEACTICAL  TEEATISE  ON  LIMES, 


one  seven  hundred  and  fifty-eighth,  while  Dalton  states  it  to  be, 
Solubility  of  lime  ^^^^^  hundred  and  seventy- 

in  water.  eighth,  and,  at   212°,  one  twelve  hundred 

and  seventieth.  The  solutions,  commonly  called  lime-water, 
are  valuable  re-agents  and  antacids.  Lime  being  more  soluble 
in  cold  than  in  hot  water,  its  solution  becomes  turbid  when 
boiled.  A  similar  result  is  produced  by  breathing  into  a  solu- 
tion through  a  tube,  owing  to  the  carbonate  of  lime  formed  by 
respiration,  which,  however,  is  dissolved  by  an  excess  of  car- 
bonic acid  gas.  A  paste  of  the  slaked  lime  is  therefore  a  mix- 
ture of  the  hydrate  of  lime  and  lime-water.  It  will  remain  in 
a  soft  condition  for  an  indefinite  period,  if  kept  in  a  damp  place, 
excluded  from  direct  contact  with  the  atmosphere. 

98.  Lime,  on  account  of  its  great  afiinity  for 

It  absorbs  moist-  .  ^      .  •       /.  ,      .        .  , 

ure  and  carbonic  moisture,  and,  when  moist,  lor  carbonic  acid, 
acid  from  the  air.  absorbs  them  gradually  from  the  atmosphere, 
returning  to  the  state  of  carbonate  of  lime,  with  an  excess  of 
hydrated  base  (CaO.COa  -f-  CaO.HO).  To  protect  it  against 
the  efiects  of  these  deteriorating  agents,  it  is  necessary  to  pre- 
serve it  in  close  vessels. 

99.  Lime  may  be  distinguished  by  its  dilute  solution  giving 

a  white  precipitate  of  oxalate  of  lime,  when  a 
Test  for  lime.  ...  ... 

solution  of  oxalic  acid  is  added  to  it,  which  is 

not  redissolved  by  an  excess  of  oxalic  acid  ;  and  by  not  yielding 

a  precipitate  with  sulphuric  acid  and  sulphate  of  soda. 

100.  The  purest  minerals  of  the  calcareous  class  are  the 
rhombohedral  prisms  of  calcareous  spar,  the  transparent  double 
The  purest  calca-  refracting  Iceland,  spar,  and  white  or  statuary 
reous  minerals.  marble.  They  are  entirely  dissolved  in  dilute 
hydrochloric  acid,  with  a  brisk  effervescence,  due  to  the  escape 
of  carbonic  acid  gas,  and  contain,  according  to  an  analysis  of  a 
specimen  of  white  marble  by  General  Treussart,  about  .33 
parts  of  carbonic  acid,  .64  of  lime,  .03  of  water.  In  pure 
carbonate  of  lime  the  lime  amounts  to  .56  of  the  whole. 

101.  The  limestones  which  furnish  the  limes  of  commerce  are 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


69 


eeldom  if  ever  pure,  but  usually  contain,  besides  the  carbonate 
of  lime  and  the  water  of  crystallization,  vari-    Limestones  are 
able  proportions,  seldom  exceeding  .10  in  the  P^^®- 
aggregate,  of  some  if  not  all  of  the  following  impurities,  viz.: 
silica,  alumina,  magnesia,  oxide  of  iron  and  oxide  of  manganese, 
and  sometimes  traces  of  the  alkalies,  the  presence  of  which 
modifies  to  a  greater  or  less  degree  the  phenom-    phenomena  devel- 
ena  developed  during  the  process  of  slaking,  as    °P®^  slakmg. 
noticed  in  paragraph  96,  and  renders  necessary  certain  precau- 
tions in  their  manipulation  and  treatment,  when  employed,  for 
the  purposes  of  construction,  as  mortars. 

102.  The  striking  and  characteristic  property  of  hardening 
under  water,  or  when  excluded  from  the  air,  conferred  upon  a 
paste  of  lime  by  these  foreign  substances,  when  their  aggregate 
amount  exceeds  .10  of  the  whole,  furnishes  the  basis  for  a  gen- 
eral arrangement  of  all  natural  or  artificial  products  suitable  for 
mortars, into  five  distinct  classes,  as  follows: 

1st.  The  common  or  fat  limes.  Their  classifica- 

tion  as  sources  of 

2d.  The  poor  or  meagre  limes.  mortar. 
3d.  The  hydraulic  limes. 
4th.  The  hydraulic  cements. 

5th.  The  natural  pozzuolanas,  including  pozzuolana,  properly 
so  called,  trass  or  terras,  the  arenes,  ochreous  earths,  schists,  grau- 
wacke  and  basaltic  sands,  and  a  variety  of  similar  substances. 

103.  Tlie  common^  fat,  or  rich  limes  usually  contain  less 

than  10  per  cent,  of  the  impurities  mentioned 

A   t  r.H       T     1  r.  1  1  •  Common  lime, 

m  paragraph  101.     in  the  process  oi  slakmg  to 

a  paste,  their  volume  is  augmented  to  from  two  to  three  and  a 
half  times  that  of  the  original  mass,  accom- 
panied by  a  hissing  noise,  an  elevation  of  tem-  ^o'umTiTskki^^^ 
perature,  and  the  rapid  and  progressive  reduc- 
tion of  the  lime  to  powder,  and  finally,  if  sufficient  water  be 
added,  to  a  homogeneous  and  consistent  paste.  With  the  ex- 
ception of  a  portion  of  the  foreign  substances  mentioned,  it  is 
soluble  to  the  last  degree  in  water  frequently  changed.  If 


70  PBAOTICAL  TREATISE  ON  LIMES 


made  into  a  stiff  paste,  it  will  not  harden  under  water,  or  evim 
,    .„    ,    in  damp  localities  excluded  from  contact  with 

The  paste  will  not  ^  ^ 

harden  under        the  air,  or  under  the  exhausted  receiver  of  an 
air-pump.    In  the  air,  it  hardens  by  the  gradual 
formation  of  carbonate  of  lime,  due  to  the  absorption  of  car- 
bonic acid  gas,  aided  by  the  deposition  of  crystals  of  hydrate 
Theory  of  its  in-    ^f  lime  from  the  lime-water  of  mixture,  during 
duration  in  the  air.  ^he  process  of  desiccation. 
■  104.  The  pastes  of  fat  lime  shrink  in  hardening  to  such  a 
deerree  that  they  cannot  be  employed  as  mor- 

CJse  of  sand.  ^    .  .  ^        ^  '^^^ 

tar  without  a  large  dose  of  sand.  When  used 
alone,  they  are  unsuitable  for  masonry  under  water,  or  for 
Lime  mortars  un-  foundations  in  damp  soils  ;  but  in  other  situa- 
suitabie  for  sub-     tions,  have  an  extensive  application,  possessing, 

aqueous  works ;  .         .  ,  ,  , 

as  they  do,  great  advantages  over  the  other 
limes  on  the  score  of  economy,  on  account  of  the  large  aug- 
much  used  under  nientation  of  their  volume  in  slaking,  their  ex- 
other  circum-        tensive  distribution  over  the  surface  of  the 

globe,  and  the  simplicity  of  their  process  of 
manufacture.  Paste  of  fat  lime  may  be  added  to  a  cement 
mortar,  in  quantities  equal  to  that  of  the  cement,  without  ma- 
terial diminution  of  strength. 

105.  The  poor  or  meagre  limes  generally  contain  silica  (in 

the  shape  of  sand),  alumina,  magnesia,  oxide 
limes ^^^^^^      of  iron,  sometimes  oxide  of  manganese,  and  in 

most  cases  traces  of  the  alkalies,  in  relative 
proportions  which  vary  very  considerably  in  different  locali- 
Amountofimpu-  ^lieir  aggregate  amount  is  seldom  less 

rities  which  they     than  .10   or  greater  than  .25,  although,  in 

contain.  ...  ,  ,  .  i 

some  varieties,  it  reaches  as  high  as  .35, 
and  even,  though  rarely,  .39  of  the  whole.  In  slaking  they 
proceed  sluggishly,  as  compared  with  the  rich  limes,  and  sel- 
dom produce  a  homogeneous  and  impalpable  powder.  They 
Phenomena  de-  exhibit  a  more  moderate  elevation  of  tempera- 
veloped  in  slaking,    ture,  evolve  less  hot  vapor,  and  are  accorapa- 


HYDEAULIC  CEMENTS,  AND  MOETAES.  7l 


nied  by  a  much  smaller  increase  of  volume  than  the  rich  limes. 

Like  the  latter,  they  dissolve  in  water  frequently  renewed, 

though  more  sparingly,  owing  to  the  presence  of  a  larger 

amount  of  impurities,  and  like  them  will  not  harden,  if  placed 

in  the  state  of  paste,  under  water  or  in  wet  soil,  or  if  excluded 

from  contact  with  the  atmosphere,  or  carbonic  acid  gas.  They 

should  be  employed  for  mortar,  only  when  it  is  impossible  to 

procure  common  or  hydraulic  lime,  or  cement, 

:      ,  .  ,  .    .  -,   T  .p  Not  to  be  used 

in  which  case  it  is  recommended,  ii  practicable,    for  mortars,  ex- 

to  reduce  them  to  powder  by  grinding.    As  a  cautions.^'' 
fertilizer,  they  have  an  extensive  application. 

106.  A  very  large  proportion,  frequently  .90  of  the  silica,  con- 
tained in  meagre  limes,  is  in  the  state  of  inert  ^^^^  ^.^.^^ 
grains  of  sand,  which  accounts  for  the  frequent  meagre  limes, 
absence  of  those  peculiar  properties  of  hardening  or  setting" 
under  water,  which  would  place  them  in  one  of  the  classes  of 
hydraulic  limes,  were  the  silica  present,  or  a  suitable  propor- 
tion of  it,  in  a  more  appropriate  form. 

107.  The  hydraulic  limes,  including  the  three  subdivisions 
of  "  limes  slightly  hydraulic,^'  "  hydraulic  Hy^^auiic  limes. 
limes,^^  and  "  limes  eminently  hydraulic^^  sel-  Three  classes, 
dom  contain  an  aggregate  of  silica,  alumina,  magnesia,  oxide 
of  iron,  &c.,  exceeding  .35  of  the  whole.  The  proportion  in 
the  first  class  ranges  generally  between  .10  and  .20  of  the 
whole ;  in  the  second  class,  between  .17  and  .24 ;  ^1^0^^^  of  impu- 
while  the  eminently  hydraulic  limes  contain  rities  which  they 
rarely  less  than  .20,  or  more  than  .35  They 

all  slake  under  proper  treatment,  though  more  slowly  than 
the  meagre  limes,  with  but  a  slight  elevation  of  temperature, 
the  disengagement  of  little  or  no  vapor,  and  but    pj^enomena  de- 

a  small  augmentation  of  volume,  rarely  ex-    veloped  in  slak- 

ing. 

ceeding  .30  of  the  original, — their  appearance 
presenting  in  this  respect  a  striking  contrast  with  the  phe- 
nomena exhibited  during  the  slaking  of  rich  limes. 

If  mixed  into  a  stiff  paste,  after  being  slaked,  they  possess 


72 


PRACTICAL  TREATISE  ON  LIMES, 


Their  paste  will  valuable  property  of  hardening  under  water, 

harden  under       in  periods  varying  from  fifteen  to  twenty  days 

water. 

after  immersion,  if  "  slightly  hydraulic  six  tc 
eight  days,  if  "  hydraulic ;"  and  one  to  four  days,  if  "  eminently 
hydraulic."  As  a  general  fact,  these  limes  undergo,  in  slaking, 
an  increase  of  volume,  inversely  proportional  to  their  hydrau- 
lic energy  and  quickness. 

108.  The  hydraulic  limes,  in  their  chemical  composition,  as 

well  as  in  those  qualities  which  confer  value  in 
^een^loSo^  their  application  to  the  purposes  of  construc- 
Uc^ceme  their  geological  position,  occupy 

an  intermediate  place  between  the  common  or 
fat  limes  and  the  hydraulic  cements.  They  are  consequently 
found  in  the  United  States  in  numerous  and  extensive  deposits ; 
but  as  they  possess  no  valuable  property  not  present  in  a  pre-emi- 
Found  extensive-  degree  in  those  limestones  which  furnish 

ly  in  the  United     hydraulic  cement,  it  has  not  been  found  neces- 

States,  but  not  *^  ,  '  , 

manufactured  for     sary,  and  certainly  it  would  not  be  remunera- 
live,  to  engage  in  any  extensive  manufacture  of 
them  for  the  trade. 

109.  The  JiydrauliG  cements  contain  a  larger  amount  of 

silica,  alumina,  magnesia,  &c.,  than  any  of  the  preceding  va- 

HydrauUc  ce-       rieties  of  lime,  though  the  amount  rarely,  if 

ment.  ever,  exceeds  .61  of  the  whole.    They  do  not 

,  ,         slake  at  all  after  calcination,  differinsr  materi- 
Will  not  slake.  .  '  5 

ally  in  this  particular  from  the  limes  proper. 

Water  does  not  pulverized,  they  can  be  formed  into  a  paste 

cause  increase  of  with  water,  without  any  sensible  increase  of 
volume,  and  with  little,  if  any  disengagement 
of  heat,  except  in  certain  instances  among  those  varieties  which 
contain  the  maximum  amount  of  lime,  or  border  on  the  "  in- 
termediate limes."  They  are  greatly  superior  to  the  best  "  emi- 
nently hydraulic  limes,"  for  all  the  purposes 

A  paste  will  har-  .  .  . 

den  quickly  under    of  hydraulic  construction  ;  some  of  them  being 
60  energetic  as  to    set"  under  water  at  65°  F., 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


73 


ill  three  or  four  minutes,  although  others  require  as  many 
hours. 

They  do  not  shrink  in  hardening  like  the  JT.ri^'td  " 
paste  of  fat  lime,  and  therefore  make  an  excel-        ^  "^^^ 

^  .  .  out  sand. 

lent  mortar  without  any  addition  of  sand ;  al- 
though, for  the  sake  of  economy,  sand,  and  frequently  both  sand 
and  lime,  are  combined  with  them.   In  the  United  States,  they 
are  almost  exclusively  depended  upon  for  hydraulic  mortar. 

110.  Lying  between  the  two  preceding  classes  in  the  amount 
of  foreign  substances  which  they  contain,  and  possessing  such 
characteristic  features  as  to  entitle  it,  perhaps,  to  a  separate 
notice,  if  not  a  separate  classification,  there  is  a  class  of  com- 
pound limestone  prominently  developed  in  the    ^  , 

^  ^  Intermediate. 

argillo-magnesian  deposits  of  this  country,  pos-    limes  of  the  Uni- 

1    T    T  n  ii       1  •         ted  States, 

sessmg  m  a  very  marked  degree  ail  the  objec- 
tionable properties  of  the  argillaceous  intermediate  limes  {chaux 
limites\  noticed  by  M.  Yicat.  "When  completely  calcined,  they 
set  rapidly,  both  in  the  air  and  in  water ;  but  in  the  latter  case 
are  soon  thrown  down  by  the  slaking  of  the  Their  charactoris- 
meagre  caustic  lime,  which  they  contain  in  ex-  feairures. 
cess.  This  result  is  brought  about  either  by  the  appearance, 
soon  after  submersion,  of  a  fine  network  of  cracks,  all  over  the 

surface  of  the  mortar,  which  gradually  pene- 

T     .        .  ,       1    -,    .        f      -,     Action  of  their 

trate  into  the  interior  until  the  whole  is  reduced    paste  under 

to  a  granulated  or  lumpy  paste,  possessing  no 

cohesion,  or,  by  the  progressive  softening  of  the  whole  mass,  to 

a  fine  and  homogeneous  pulp,  frequently  accompanied  in  either 

case  with  a  considerable  enlargement  of  volume. 

If,  after  the  action  of  the  water  has  commenced,  as  indicated 

either  by  the  appearance  of  cracks,  or  by  a  general  softening 

upon  the  surface,  the  paste  be  again  worked  up  with  the 

trowel,  dried  off  with  bibulous  paper,  formed    ^  , 

'  r  JT     7  Destruction  of 

into  a  stiff  cake  and  immersed,  the  same  phe-    hydraulic  energy 

nomena,  though  in  a  more  moderate  form,  will 

frequently  exhibit  themselves  again,  and  with  some  varieties, 


PEAOTICAL  TEHATISE  ON  LIMES, 


will  not  entirely  disappear,  until  four  or  five  repetitions  of  this 
process.  This  is  particularly  the  case  with  some  of  the  layers 
in  Ulster  county,  N^.  Y.  In  all  cases,  however,  whether  one  or 
several  remixings  suffice,  the  hydraulic  energy  is  so  far  im- 
paired that  the  substance  cannot  assume  a  higher  rank  than 
hydraulic  lime,  requiring  from  three  to  ten  days  to.  harden 
sufficiently  to  support  the  2V  inch  wire  loaded  to  one  pound. 
When  considerably  underburnt,  these  limestones  yield  a  good 
cement.     They  ought  not,  under  any  circum- 

Not  to  be  used  for  1      •         i  i 

mortar,  except  stance,  to  be  introduced,  even  m  a  small  pro- 
caution  ^^^"^  P^^i'tion,  into  any  combination  which  is  intend- 
ed to  be  kept  up  to  the  standard  of  good  ce- 
ment, without  being  subjected  to  a  calcination  by  themselves ; 
and  even  then  it  will  be  found  extremely  difficult,  if  not  prac- 
tically impossible,  to  so  regulate  the  heat  that  all  the  stone 
shall  be  suitably  underburnt. 

111.  The  natural  pozzuolanas  comprise  pozzuolana  properly 
Natural  pozzuo-  so-called,  trass  or  terras,  the  arenes,  some  of 
lanas.  the  ochreous  earths,  and  the  sand  of  certain 

grauwackes,  psammites,  granites,  schists,  and  basalts.  Their 
Principal  ingredi-  principal  ingredients  are  silica  and  alumina, 
ents  thereof.  with  a  large  preponderance  of  the  former. 
Most  varieties  contain  small  quantities  of  soda,  potash,  ox- 
ides of  iron  and  manganese,  and  not  unfrequently  magnesia. 

None  of  them  contain  more  than  .10  of  lime, 
when  pulverized  When  finely  pulverized  without  previous  cal- 
and  mixed  with  cination,  and  combined  with  the  paste  of  fat 
lime  in  suitable  proportions,  to  supply  their 
deficiency  in  that  ingredient,  they  possess  hydraulic  energy  to 
a  degree  that  will  compare  favorably,  in  some  of  the  varieties, 
with  that  of  the  "  eminently  hydraulic  limes."    Those  de- 

.  ^.   .      rived  from  the  disinteo^ration  of  ^rauwacke, 
Some  varieties  im-  o  °  ' 

proved  by  calci-     psammite,  granite,  and  the  other  rocks  men- 
tioned, are  the  least  energetic  of  the  class,  and 
are  somewhat  improved  by  a  slight  calcination. 


HYDEAULIC  CEMENTS,  AND  MORTAES.  75 


112.  Pozziwlana^  which  confers  the  name  upon  this  class  of 
substances,  is  of  volcanic  origin,  and  has  therefore  been  sub- 
jected to  the  action  of  heat,  whereby  its  constituent  elements 
have  experienced  a  chemical  change  in  their  primitive  mode  of 
combination.    It  w^as  originally  discovered  at 
the  foot  of  Mount  Yesuvius,  near  the  village  of   origin.  ' 
Pozzuoles,  whence  its  name,  although  it  is  com- 
mon to  all  localities  that  have  been  exposed  to  igneous  agency, 
being  found  sometimes  upon  the  surface  of  the  earth,  though 
most  generally  in  beds,  which  frequently  extend  to  considerable 
depths.   It  is  extensively  disseminated  through- 
out Europe,  and  large  quantities  for  building  f^^rope'''''^^^^ 
purposes,  have  been  derived  from  the  vicinity 
of  Rome  and  Civita  Yecchia,  in  Italy,  and  from  the  Puy-de- 
Dome,  Upper  Yienne,  Upper  Loire,  Cantal  and 

'  .  V   -r^  T   .     1      .       T  .    r..  .1  Localities. 

Yivarais,  m  France.    It  is  also  found  m  Sicily, 

in  the  Isle  of  France,  and  in  Guadaloupe  and  Martinique.  It 

sometimes  exists  in  a  coherent  form,  but  more  frequently  is 

either  pulverulent  or  in  coarse  grains,  sharp,  angular,  and  rude 

10  the  touch.    Its  prevailing  color  is  brown,    ^  ^ 

with  many  exceptional  shades  of  red,  violet, 

gray,  and  yellow,  and  oftentimes  approaching  white  and  black. 

It  is  hipjhly  magnetic,  parts  with  about  .09  of 

,  .       .        .  T        ,  .         T  Properties, 

water  by  calcination,  is  entirely  solvent  m  sul- 
phuric acid,  and  in  concentrated  hydrochloric  acid  at  the  boil- 
ing point.    As  might  be  inferred,  from  the  character  of  the 
agencies  v/hich  produce  pozzuolana,  its  hydraulic  properties 
differ  very  much  in  different  localities. 

Its  value  for  the  purposes  of  construction  in  combination 
with  rich  lime,  has  been  known  for  many  centuries,  and  Yitru- 
vius  and  Pliny  both  speak  of  its  admirable  properties,  as  exhi- 
bited in  the  marine  constructions  of  the  Pomans, 
extant  in  their  day.    In  using  pozzuolana,  it  is  '^^^ 
customary  after  pulverizing  it,  to  add  sand  as 
well  as  lime  ;  the  relative  proportion  of  the  three  ingredients 


76 


PEACTICAL  TREATISE  ON  LIMES, 


depending  on  the  kind  of  sand  employed,  and  the  character  of 
the  lime  and  pozzuolana.  For  the  Italian  pozzuolana,  there  ia 
perhaps  no  better  combination  than  that  recommended  by 
Yitruvius  himself,  which  has  been  followed,  with  slight  varia- 
tions,  very  generally  throughout  Italy,  and  at  Toulon,  and  other 
ancient  ports  on  the  French  coast.    It  is  as  follows,  viz. : 

12  parts  of  pozzuolana  well  pulverized, 
6    "     "  quartzose  sand  well  washed, 
9    "     "  rich  lime  recently  slaked ;  to  which  is  added 

6    "     "  fragments  of  broken  stone,  porous  and  angular,  when  it  is  intended 
for  a  pise  or  a  filling  in. 

,  ,         The  pozzuolanas  of  this  country,  if  any  exist. 

Not  known  to  be  ^  ^  j.jj 

native  to  the        have  never  been  used  in  constructions,  and  have 

United  States.  •      t     •  i  i 

never  been  examined  with  that  view. 

113.  Trass  or  terras. — In  the  valley  of  the  Rhine  between 
Mayence  and  Cologne,  and  in  various  localities  in  Holland,  a 
substance  of  volcanic  origin  is  found,  called  Trass  or  Terras, 
^  which  has  been  extensively  employed  through- 
out that  region,  particularly  by  the  Dutch  engi- 
neers, for  the  production  of  hydraulic  mortar.    It  is  derived 

from  immense  pits  or  quarries,  occupying  the 
Its  sources.  ^«     .       i  j      •        •  i 

Sites  01  extmct  volcanoes,  and  enjoys  m  nearly 
every  particular  the  distinguishing  properties  of  Italian  poz- 
zuolana, closely  resembling  it  in  its  composition, 
zuda^a^^and^^s'  details  of  its  manipulation,  requiring 

used  m  the  same  pulverized  and  combined  with  rich  lime, 

manner.  ^  ' 

in  order  to  render  it  fit  for  use,  and  to  develop 

any  of  its  hydraulic  properties. 

114.  The  trass  used  in  Holland  is  obtained  principally  from 

Bonn,  Andernach,  and  from  the  village  of  Dor- 
Dutch*trass^         dreck,  exclusively  devoted  to  its  production,  and 
at  the  confluence  of  the  Rhine  and  the  Meuse. 

115.  Trass  is  of  a  grayish  color,  has  an  earthy  appearance, 

and  is  found  in  beds  that  are  sometimes  co- 
herent, though  usually  composed  of  a  bete- 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


77 


rogeneoiis  mass  of  pulverulent  lumps,  from  the  size  of  a 
small  pea  to  that  of  an  egg.  Sulphuric,  and 
even  concentrated  hydrochloric  acid,  attacks  it  -^^^^P®^^®^- 
with  readiness,  leaving  a  residue  of  insoluble  silica.  Smeaton 
regarded  it  as  inferior  to  the  Italian  pozzuolana  in  some  essen- 
tial particulars,  and  mentions,  as  one  of  its  objectionable  fea- 
tures, that  of  throwing  out  unsightly  efflorescences  upon  the 
faces  of  walls  in  which  it  is  used,  which  attain  such  a  degree  of 
hardness,  as  to  render  their  removal  with  instruments  necessary, 
specially  in  positions  where  smoothness  and  regularity  of  sur- 
face are  essential,  as  in  water  conduits,  navigable  sluices,  &c. 

More  recent  experiments  have  led  to  the  suspicion  that  Smea- 
ton either  made  use  of  a  lime  ill  adapted  to  the  purpose,  or  what 
is  perhaps  more  probable,  that  he  unduly  augmented  its  propor 
tion,  which  should  rarely  exceed  the  ratio  of  one  to  one. 

116.  Arenes  is  the  name  given  to  a  species  of  ochreous  sand, 
claimed  by  some  to  be  of  fossil  orisfin,  and 

Arenes. 

found  abundantly  in  France,  in  the  Depart- 
ment of  Dordogne,  and  in  several  localities  on  the  tributaries 
of  the  Loire  and  the  Somme.     On  account  of  the  large  pro- 
portion of  clay  which  many  of  them  contain, 
which  often  reaches  as  high  as  .70,  they  can  be    ^[thouf  i^e!^ 
formed  into  a  paste  with  water,  without  any 
addition  of  lime,  and  are  often  used  in  that  state  for  the  walls 
of  buildings  constructed  en  pise^  as  well  as  for  mortar. 

Mingled  with  rich  lime,  they  give  apparently  excellent 
mortars,  which  attain  great  hardness  under  water ;  and,  in 
hydraulic  quickness,  compare  favorably  with  the  most  ener- 
getic hydraulic  limes. 

117.  It  is  doubtful,  from  some  careful  experiments  that 
have  been  made,  whether  their  properties,  as  regards  the  ulti- 
mate strength  and  hardness  of  the  mortars       •  ^  . 

^  ^      ^  Their  hydraulic 

made  from  them,  are  improved  by  calcination,    activity  increased 
or  otherwise.    Their  hydraulic  quickness,  how-  burning, 
ever,  is  greatly  increased  thereby.  Their  colors  are  various,  such 


78 


PEACTICAL  TREATISE  ON  LIMES, 


as  red,  brown,  yellow,  and  sometimes  white.    They  contain 
from  .10  to  .70  of  clay,  the  balance  beinff  a 

Oompositiou. 

mixture  oi  coarse  and  nne  calcareo-siiicious 
sand  ;  and  have  hitherto  been  principally  found  upon  the  sum- 
mits of  small  hills,  or  forming  the  superior  strata  of  plateaux 
bordering  water-courses,  but  rarely  in  the  valleys.  These 
beds  exhibit  the  characteristic  physical  features  of  alluvial 
deposits,  and  are  probably  accretions  of  diluvial  or  tertiary 
earths,  transported  from  a  distance.  This  conclusion  excludes 
the  idea  that  they  have  been  subjected  to  the  action  of  vol- 
canic heat,  and  leaves  us  to  account  by  some  other  hypothesis 
for  their  hydraulic  properties,  and  their  close  resemblance,  in 
other  respects,  to  the  Italian  pozzuolana.  The  most  reason- 
able supposition  is  that  they  owe  their  hydraulic  energy,  when 
mixed  with  the  paste  of  fat  lime,  to  the  presence  of  silica,  not 

in  the  state  of  quartz,  but  in  a  form  favorable 
SethydSdty^^  free  combination  with  the  lime,  in  the 

production  of  an  insoluble  silicate.  To  account 
for  the  hydraulic  energy  in  crude  arenes  requires  a  more 
lengthy  discussion  of  certain  chemical  reactions,  than  can  with 
propriety  be  introduced  here.  It  will  therefore  be  deferred  to  the 
chapter  containing  the  "  theory  of  the  subaqueous  induration." 

118.  When  the  arenes  were  first  discovered,  great  attention 
was  paid  to  their  examination,  and  with  such  favorable  results 
at  the  outset,  that  they  immediately  took  rank  among  the 
most  valuable  sources  of  hydraulic  mortar.  Subsequent  experi- 
ments, however,  have  not  fully  realized  the  high  expectations 
originally  entertained  with  regard  to  them,  or  verified  their 
claims  to  any  superiority  in  initial  energy  over  the  pozzuolana 
and  trass  ;  while  the  efiects  of  time  upon  the  mortars  composed 
of  them,  have  established  the  fact  that,  with  few  exceptions, 
they  should  be  classed  among  the  most  feeble  pozzuolanas,  that 
they  contain  ingredients  which  exercise  a  hurtful  influence 
upon  mortars  in  the  air,  and  that  immersed  in  water,  they  at 
tain  but  a  medium  degree  of  ultimate  hardness. 


HTDEATTLIC  CEMENTS,  AND  MOETAES. 


79 


119.  Properties  similar  to  those  possessed  by  Llie  arenes  have 
been  discovered  in  grauwacke,  psammite,  granite,  scliist,  basalt, 
and  other  rocks,  when  in  a  state  of  disintegra- 
tion.   They  must,  however,  be  considered  as  natural 

-J  '  '  pozzuolanas. 

verj  feeble  pozzuolanas,  in  the  crude  state,  and 
acquire  but  a  slight  increase  of  hydraulic  energy  by  any  degree 
of  calcination.  Even  their  feeble  powers,  however,  confer  upon 
them  this  advantage,  that,  for  mortars  not  absolutely  immersed 
in  water,  when  green,  and  when  there  is  ample  time  for  their 
properties  to  develop  themselves  before  submersion,  they  can 
be  employed  in  larger  proportions  than  any  species  of  sand, 
wholly  inert,  would  admit  of. 

120.  It  may  be  said  that  a  mortar  has  set^  when  it  has  at- 
tained such  a  degree  of  induration,  that  its  form  cannot  be 
altered  without   causing  a  fracture,  that  is, 

when  it  has  entirely  lost  its  plasticity.    As  the  rmortlTdefined 
precise  moment  when  this  takes  place  is  some- 
what difficult  to  ascertain  in  practice,  it  is  important  that  some 
more  rigorous  standard  of  comparison  should  be  established. 
The  common  method  is  to  make  use  of  an  iron  or  steel  wire 
point  loaded  to  a  given  wsight ;  and  the  mor- 
tar is  assmned  to  have  set,  when  it  has  become  Si^tfmeo^setting. 
sufficiently  stiiF  and  firm  to  support  the  point 
without  depression. 

121.  Some  cements  are  remarkably  quick  in  exhibiting  their 
hydraulic  property,  and  will  lose  their  plastic  state  immersed 
in  water  at  65°  F.  in  one  or  two  minutes,  but  afterwards  pro- 
ceed very  sluggishly  in  their  induration.  These,  therefore, 
Betting  aside  the  question  of  their  value  in  other  respects,  are 
admirably  adapted  to  constructions  under  water,  or  in  positions 
subjected  to  immediate  submersion.  There  are  others,  again, 
which,  though  comparatively  slow  in  developing  the  first  in- 
dications of  hydraulic  energy,  yet  in  a  few  hours,  greatly  sur- 
pass the  former  in  withstanding  the  wire  test,  as  well  as  in 
their  ultimate  strength  and  hardness,  and  are  therefore  to  be 


80 


PEACTICAL  TREATISE  OlS  LIMES, 


preferred  in  all  positions  where  a  very  quick  induration  is  not 
^    T     ^-      specially  important.    The  former  are  remark- 

"  Hydraulic  activ-      ^  ^  i 

ity"  and  "  hydrau-    able  for  what  we  propose  to  term  hydraulic 

lie  GDcrsrv,"  .  . 

quickness  or  activity  ;  the  latter,  for  hydraulic 

energy  or  power.    In  order  that  we  may  be  able  to  detect  and 

recognize  these  somewhat  obscure  properties,  it  is  necessary  to 

have  at  least  two  testing  wires,  which  differ  either  in  their  size, 

or  weight,  or  in  both.    General  Totten,  for  his  experiments, 

carried  on  at  Fort  Adams,  H.  I.,  during  several  years  prior  to 

1830,  used  a  j\  inch  wire,  loaded  to  weigh  J  of  a  pound,  and  a 

»V  inch  wire,  loaded  to  weisrh  one  pound.  We 

Testing  wires.         f*  ^     '  .      -n  ,  .  . 

have  used  the  same  m  ail  our  tests,  makmg  in 

every  instance  two  cakes  of  the  mortar  under  consideration,  by 
forming  them  in  a  circular  mould  or  ring  inch  in  diameter, 
and  |-  inch  deep.  As  soon  as  these  cakes  are  prepared,  whicli 
is  done  by  pressing  the  mortar  into  the  ring  with  a  spatula, 
and  smoothing  off  the  upper  surface,  one  of  them  is  immersed 
immediately  in  water  of  an  established  temperature  (65^  F.),  and 
the  periods  of  time  which  it  requires  to  be  able  to  bear  respect- 
ively the  inch  wire,  weighing  J  of  a  pound,  and  the  ^\  inch 
wire,  weighing  one  pound,  are  accurately  noted  by  the  watch. 
The  other  cake  is  left  in  the  air  (also  brought  to  65^  F.),  until  it 
supports  the  ii^ch  wire,  and  is  then  immersed  in  water,  and 
the  time  required  to  bear  the  small  wire  and  heavy  weight 
ascertained. 

122.  The  wire  test  of  hydraulic  activity,  when  applied  to 
cement  paste  without  sand,  does  not  furnish 

Wire  test  of  pure  .  .    , .      .        ^   ,        ,  . 

oement  paste  not    even  an  approximate  indication  of  the  relative 

reliable.  value  of  mortars  of  the  same  cements  when  mixed 

with  a  full  dose  of  sand ;  for  a  quick  cement  might  contain 

one-half  or  three-fourths  of  its  volume  of  inert  matter  ground 

up  with  it,  and  consequently  be  incapable  ol 
Roasonswhy.  ^   ,  ,        '  -,        -,      .-n  ,  . 

receivmg  much  sand,  and  still  be  superior  in 

hydraulic  activity  to  another,  although  the  latter  might  bo 

entirely  unadulterated  and  its  capacity  for  sand  unimpaired. 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


81 


In  pronouncing  on  the  value  of  cements,  from  a  comparison  of 
their  relative  hydraulic  activity,  they  should, 
therefore,  be  mixed  with  two  and  a  half  to  three    ^|  to^brused. 
times  their  volume  of  sand.  Even  with  this  pre- 
caution, the  result  is  far  less  reliable  than  some  simple  device 
for  trying  the  strength  of  the  mortars,  when  ten  or  twelve 
days  old.    As  an  evidence  of  the  truth  of  this  remark,  it  may 
be  stated  that,  although  eminent  hydraulic  activity  or  quick- 
ness is  not  necessarily  accompanied  by  inferior  hardness  and 
strength,  and  conversely,  neither  is  a  slow  setting  cement 
necessarily  a  strong  one  ;  still,  within  the  range  of  the  experi- 
ments which  furnish  the  tables  of  this  work,  it  is  somewhat 
remarkable  that  the  quickest  cements  gave  the  worst  results, 
and  the  slowest  ones  the  best. 

123.  The  efiects  of  a  variation  of  temperature  upon  the 
hydraulic  quickness  of  mortars,  whether  derived  from  hydraulic 
lime,  hydraulic  cement,  a  mixture  of  common  lime  and  pozzu- 
olana,  or  produced  by  artificial  means  is  very    ^^^^^  change 

marked;  so  much  so  indeed,  that  in  all  compar-    of  temperature  on 

hydraulic  activity. 

ative  tests  of  this  kind,  it  is  important  to  adopt 

some  fixed  standard  of  temperature,  not  only  for  the  water  with 

which  the  cement  is  mixed,  as  well  as  that  in  which  the  cement 

is  immersed,  but  for  the  dry  ingredients  and  the  surrounding 

atmosphere. 

To  illustrate  the  necessity  for  these  precautions,  we  will  in- 
stance two  kinds  of  United  States  cements.  With  the  dry 
cement  and  water  for  mixing  at  90°F.,  one  of  these  cements 
immersed  in  the  state  of  paste  in  water  at  90°  F.,  supported  the 
yV  i^ich  wire  loaded  to  J  of  a  pound  in  1^  minutes.    The  other 

one  required  4  minutes  to  attain  the  same  set.  ,     .  , 

^  Examples  cited. 

Lowering  the  temperatures  to  65^,  the  former 

required  6  minutes,  and  the  latter,  17  minutes ;  while  at  35*^,. 

the  respective  periods  were  lengthened  to  39  and  82  minutes^ 

showing  for  a  depression  of  55^  in  the  temperature  of  the"  paste 

(viz. :  from  90^^  to  35*^),  a  corresponding  prolongation  of  the 

6 


82 


PRACTICAL  TREATISE  ON  LIMES, 


period  required  to  set,  amounting  in  the  one  case,  to  37^ 
minutes,  and  in  the  other,  to  one  hour  and  18  minutes. 

Hence,  all  cements  are  not  equally  sensitive  to  a  variation 
of  temperature ;  also,  those  varieties  which  contain  an  excess 
Deduct'ons       ^  caustic  lime  may  exhibit  a  superior  degree  of 
hydraulic  activity^  due  to  the  heat  generated  in 
bringing  this  lime  to  the  state  of  hydrate. 

124.  The  diagram  (Figure  8)  is  intended  to  show  the  effect 
of  a  variation  of  temperature  upon  the  time  of  setting  of 
cements  formed  into  cakes  or  cyh'nders  of  stifi  paste,  as  de- 
scribed, paragraph  121,  immersed  in  that  condition  in  water. 

The  curves  are  constracted  with  abscissas,  which 
Sa^r^*^^^         represent  the  temperature  of  the  air,  water,  and 

dry  cement  (these  being  varied  equally  and 
kept  together  in  all  cases),  and  with  ordinates,  which  repre- 
sent the  times  of  setting,  in  minutes,  that  is,  the  period  of 
time  which  elapses  before  the  immersed  paste  can  support  the 
loaded  wire  point  without  depression.  The  dotted  curves  refer 
to  tests  with  yV  inch  wire,  loaded  to  |  pound,  and  the  full 
curves  to  the  2V  i^^ch  wire,  loaded  to  one  pound. 

OBSERVATIONS  ON  THE  DIAGRAM,  FiG.  8. 

Ko.  1  is  from  the  Round  Top  Cement  Works,  on  the  Poto- 
mac River,  near  Hancock,  Md.  (See  paragraph  75.)  This  is 
a  very  quick  setting  cement,  whether  left  in  the  air,  or  im- 
mersed in  water.  For  masonry,  or  concrete  work  in  running 
water,  when  it  is  necessary  to  carry  on  operations  in  cold 
weather,  the  dotted  curve  indicates  that  no  cement  in  the 
country  is  superior  to  it  in  rapidity  of  first  induration.  It  sus- 
tains a  change  of  temperature  better  than  any  cement  tried, 
except  Ko.  3. 

No.  2  is  from  the  James  River  Works,  at  Balcony  Falls,  Rock- 
bridge Co.,  Ya.  For  all  temperatures  above  55°,  this  cement 
exceeds  in  hydraulic  activity,  all  the  specimens  submitted  to 
trial ;  while  below  48°  it  is  surpassed  by  only  two,  the  Round 


HYDEAULIC  CEMENTS,  AND  MORTARS. 


83 


Top  and  the  Cumberland  (No.  3).  At  all  temperatures  it  sets 
in  the  water  almost  as  quickly  as  it  will  in  the  air.  (See  para- 
graph 79.) 


90"     85°       80°       75"      70"       65°      60"       55        50"      45°      40°  SI 


Temperature  of  water,  dry  cement,  and  »ir. 
Fig.  8. 


84 


PRACTICAL  TREATISE  01^  LIMES, 


'No.  3  is  from  the  Cumberland  cement.  (See  paragraph  77.) 
It  is  less  sensitive  to  a  depression  of  temperature  than  any  ex- 
hibited in  the  diagram. 

No.  4  belongs  to  the  ITewark  and  Rosendale  brand,  from 
Ulster  Co.,  N.  Y.,  and  is  a  fair  type  of  the  dark-colored  Rosen- 
dale  cements.    (See  paragraph  61.) 

No.  5  is  a  light-colored  Rosendale  cement,  manufactured  at 
High  Falls  by  Messrs.  Delatield  &  Baxter.  (See  paragraph 
63.) 

By  examining  the  above-mentioned  curves,  a  marked  differ- 
ence is  observed  between  No.  1,  No.  2,  and  No.  3,  as  compared 
with  No.  4  and  No.  5.  At  high  temperatures,  they  all  begin 
to  harden  under  water  with  nearly  equal  promptness,  requirin  g 
less  than  five  minutes  to  bear  the  light  testing  wire  ;  while  at 
two  degrees  above  the  freezing  point,  the  James  and  Potomac 
River  cements  set  in  periods  varying  from  twenty-seven  to 
thirty-eight  minutes,  while  the  Rosendale  brands  require 
seventy-two  and  eighty-four  minutes  respectively.  The  latter 
are  therefore  more  sensitive  to  a  variation  of  temperature  than 
the  former. 

No.  6  belongs  to  a  cement  from  Sandusky,  Ohio.  (Para- 
graph 81.)  This  cement  is  characterized  by  a  remarkable  w^ant 
of  uniformity  in  quality,  as  it  is  offered  in  the  market.  One 
sample  obtained  in  the  summer  of  1859,  required  several  hours 
under  water  at  65°  F.,  before  it  could  support  the  light  testing 
wire  (^2  inch  wire  and  }  pound  weight),  and  would  not  supporl 
the  heavy  wire  until  the  second  day  after  immersion.  Anothei 
specimen,  obtained  several  months  later,  gave  for  the  light  test- 
ing wire  the  curve  No.  6.  The  cement  hardened  so  slowly 
after  the  first  set,  that  the  curve  for  the  heavy  wire  does  not 
come  within  the  limits  of  the  diagram. 

No.  7  belongs  to  the  cement  manufactured  at  Utica,  111 
(See  paragraph  80.)    It  closely  resembles  that  from  Sandusky, 
Ohio,  although  it  conducts  itself  under  water  rather  more  satis- 
factorily.   By  mixing  the  Sandusky  and  Utica  cements  to- 


hyi>kac"l:o  cements,  and  mortaes.  85 


getlier,  :n  equal  quantities,  a  combination  is  obtained,  which 
from  experiments  carefully  repeated  on  a  small  scale,  appears 
to  be  superior  to  either.  It  is  therefore  suggested  to  Western 
engineers  and  architects  to  use  them  in  this  way. 

'No.  8  is  derived  from  an  artificial  cement  prepared  from  a 
stiff  paste  of  fat  lime  mixed  up  with  a  sufficiency  of  double  al- 
kaline silicate,  of  39°  Baume,  in  solution  to  bring  it  to  the  con- 
sistency of  ordinary  mortar.  Almost  any  required  degree  of 
hydraulic  activity  may  be  conferred  upon  a  paste  of  fat  lime 
in  this  way.  Limes  that  have  been  allowed  to  remain  some 
days  in  the  state  of  paste  before  adding  the  silicate,  are  pref- 
erable to  those  that  have  been  slaked  to  a  powder  and  pre- 
served in  that  condition.  These  latter  are  apt  to  crack  under 
water,  after  the  silicate  has  been  added. 

No.  9  was  from  Roman  cement  manufactured  from  "  Sep- 
taria,"  or  clay  nodules  found  on  the  coast  of  Scotland.  It  is 
proper  to  remark,  that  this  cement  bore  evidences  of  having 
suffered  from  exposure  during  transportation,  and  was  not 
therefore  so  fresh,  and  of  course,  not  so  energetic  as  an  average 
sample  would  have  been.  In  hydraulic  quickness,  fresh  Ro- 
man cement  is  by  no  means  inferior  to  the  best  Rosendale 
brands,  while  its  subsequent  progressive  induration  probably 
exceeds  that  of  most  American  cement. 

No.  10  is  from  the  cement  manufactured  at  Louisville,  Ky. 

Artificial  Hydraulic  Cement  and  Lime. 

125.  It  is  possible  to  make  hydraulic  mortar  by  using  arti- 
ficial  preparations  of  hydraulic  cement,  lime.    Artificial  hydrau- 
and  pozzuolana,  and  this  course  is  often  pursued,  mortar, 
particularly  in  France,  in  localities  where  there  are  no  naturai 
deposits  suitable  for  such  purposes.    There  are    ^^^^  methods  of 
four  methods  of  attaining  this  object,  viz. :  making  it. 

First,  by  combining  thoroughly  slaked  common  lime  with 

unburnt  clay  in  suitable  proportions,  burnins: 

•  ^        •         T       T  i  ^  f    First  method, 

the  mixture  in  a  lime-kiln  or  furnace,  and 


86 


PEACTICAL  TREATISE  ON  LIMES, 


then  grinding  it,  producing  what  is  called  twice-kilned  "  arti- 
ficial hydraulic  lime." 

Second,  by  substituting  for  the  quicklime  a  carbonate  of 

lime  that  can  be  pulverized  without  burning, 
Second  method.  in.      ,^  n  ^^      -        t  t 

like  chalk,  m  other  respects  lollowing  the  direc- 
tions of  the  first  process. 

Third,  by  making  artificial  pozzuolana,  which  is  effected 

whenever  calcareous  sand  and  certain  kinds  of 
Third  method.  ,  .  . 

clay  are  subjected  to  a  slight  calcination. 

Fourth,  by  adding  silica,  in  a  soluble  form,  to  a  paste  of 

Fourth  method.      common  lime. 

FIEST  METHOD. 

126.  Before  the  calcination,  the  clay  should  be  fully  dried  in 

the  open  air,  or  under  sheds  prepared  for  the 
Drying  the  clay.  p.  /i.  •  i         a  ^ 

purpose,  alter  the  manner  oi  bricks  and  pot- 
tery. The  proportion  of  lime  and  clay  used  should  be  varied 
Proportion  of       according  to  the  quality  of  the  clay,  the  charac- 

Ume  and  clay.  ^^^.j^^       ^j^^  j-^^^^  ^j^^  degree  ol 

hydraulic  quickness  which  the  resulting  product  should  possess, 
that  is,  whether  it  is  intended  to  imitate  hydraulic  cement  or 
hydraulic  lime.  Ten  per  cent,  of  clay  will  confer  "moderately 
hydraulic"  energy,  while  it  will  never  be  necessary  to  exceed 
54  per  cent,  to  produce  a  very  active  cement.  The  clays  that 
Kinds  of  clay  have  been  found  most  suitable  for  that  purpose 
most  suitable.  a^e  those  which  are  unctuous  to  the  touch,  and 
are  of  common  use  for  manufacturing  various  kinds  of  earthen- 
ware. They  contain  .30  to  .50  of  alumina,  and  .04  to  .05  of 
carbonate  of  lime.  It  is  of  the  highest  importance  that  the 
lime  and  clay  should  be  thoroughly  and  homogeneously  incor- 
porated with  each  other  by  means  of  a  mortar  mill,  if  prac- 
ticable, previous  to  the  drying  process,  and  that  this  latter 
should  be  continued  until  no  trace  of  humidity  remains.  If 
this  last  condition  be  not  fulfilled,  no  good  results  can  be  ob- 
tained, as  the  silica  contained  in  the  clay  will  not  be  in  a  state 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


87 


favorable  to  its  combination  with  the  lime  in  the  dry  way,  and 
the  clay  will  remain  almost  entirely  inert,  from  the  moment 
the  mixture  reaches  a  dull  red  heat.  These  facts,  originally 
promulgated  by  M.  Rancourt,  have  been  amply  verified  by 
repeated  experiments  conducted  by  M.  Ducreux  and  others. 
To  prepare  the  mixture  of  lime  and  clay  for  preparation  of 
drying  and  burning,  it  is  customary  to  cut  mixture  for  biim- 
it  up  into  small  cakes,  or  roll  it  into  balls  of  two 
or  three  inches  diameter. 

127.  The  calcination  is  efi*ected  at  a  lower  temperature  than 
that  required  by  the  natural  stone  ;  a  bright  calcined  at  a  low 
red  heat  is  sufficient,  as  water  is  more  easily  dis-  temperature, 
engaged  from  the  cakes  than  carbonic  acid  would  be.  It  is 
also  necessary  that  this  second  calcination  should  take  place  un- 
der the  influence  of  a  good  draught,  or  in  contact  with  the  air. 
The  material  thus  obtained  is  said  by  M.  Yicat  to  be  prefer- 
able to  the  best  hydraulic  limes  directly  obtained  from  argil- 
laceous limestones,  but  we  shall  see  further  on,  that  this  is  at 
least  doubtful.  A  saving  of  fuel  can  be  effected  by  burning 
raw  bricks,  or  common  lime,  or  both,  in  the  same  kiln,  with  the 
argillo-calcareous  balls,  and  this  is  practised  in  many  countries. 
It  can  be  done  in  kilns  somewhat  higher  than  the  average,  say 
eighteen  feet,  filling  them  with  carbonate  of  lime  up  to  nine  and 
a  half  or  ten  feet,  placing  over  it  bricks  to  a  height  of  five  feet, 
and  over  the  latter,  the  small  pieces  of  lime  and  clay  which 
have  to  be  converted  into  hydraulic  lime.  The  burnt  balls 
may  be  pulverized  between  millstones,  or  by  any  other  suitable 
means. 

SECOISTD  METHOD. 

128.  When  a  soft  carbonate  of  lime,  like  chalk,  or  calcareous 
tufa,  is  employed  for  making  artificial  hydraulic  lime  or  cement, 
it  is  not  necessary  or  customary  to  subject  it  to    ^^^^  and  clay 
calcination,  previously  to  its  being  mixed  with    mixed  together 
the  clay.    The  reduction  of  both  ingredients    ^^^^^  burnmg. 


88 


PRACTICAL  TREATISE  ON  LIMES, 


to  a  fine  powder  by  suitable  machinery,  li(^wever,  is  essential 
as  the  first  step ;  after  which  they  are  thoroughly  mixed 
together  in  proportions  ascertained  by  previous  experiments  to 
give  the  desired  results,  made  into  cakes  or  balls,  dried,  cal- 
cined, and  ground  for  use,  as  in  the  first  case. 

The  "  Portland"  cement  of  England  and  France*  is  made 

in  this  way,  the  calcination  being  carried  to  the 
laid^^ceinent^^'     ^'^rge  of  vitrification.   In  its  manufacture,  chalk 

is  generally  depended  on  to  furnish  the  calcare- 
ous ingredient.  The  necessity  of  reducing  the  carbonate  to  a 
state  of  paste,  and  of  incorporating  it  with  tlie  clay  before  any 
calcination  takes  place,  practically  excludes  the  more  compact 

varieties  of  limestone.  The  chalk  may  be 
amm.^^^^^        ground  in  any  mill  suitable  for  reducing  such 

substances.  One  consisting  of  a  circular  trough 
of  stone  or  brick  work,  in  which  two  wheels  are  made  to  turn, 
has  been  used  in  England,  and  found  to  answer  a  good  pur- 
pose. The  wheels  are  located  on  the  axis  at  unequal  distances 
from  the  centre  of  motion,  so  as  not  to  run  in  the  same  track. 
For  extensive  operations,  a  steam  mortar  mill  like  the  one  used 
at  Fort  Taylor  (Figure  34),  or  some  modification  of  it,  would 
perhaps  possess  many  advantages. 

129.  Water  is  added  to  the  chalk  before 
lu^rp^s^oTwater'!    grinding,   generally  in  considerable  surplus. 

After  this  preliminary  manipulation  is  com- 
pleted, the  semi-fluid  mass  is  conveyed  into  bins  with  grated 
or  perforated  bottoms,  or  made  up  into  heaps  and  left,  until,  by 
drainage  and  evaporation,  it  is  reduced  to  the  consistency  of 
stiff  mortar.  It  is  then  in  a  condition  to  be  mixed  with 
the  clay.  Pwre  oUuvial  clay,  or,  when  this  cannot  be  pro- 
cured, fine  pit  clay,  free  from  sand,  is  next 
eSabie.^^^^         added  to  the  chalk  paste,  and  the  thorough  and 

homogeneous  incorporation  of  the  two  ingredi- 
ents is  effected  by  means  of  a  pug-mill.  For  the  English  Port* 

*  The  "  artificial"  Portland  is  here  referred  to. 


HYDEAULIC  CEMENTS,  AND  MOETAKS. 


89 


land,"  the  ai'gillaceous  mud  deposited  by  the  Tliaraes  and  Med- 
way  Rivers  is  used.    The  chalk  is  derived  from 

,  .  The  chalk  used. 

the  middle  and  upper  layers  oi  that  lormation, 
as  it  crops  out  on  the  banks  of  the  Thames.  These  sub- 
stances are  ground  up  together  by  millstones,  v^^ith  a  sufficiency 
of  water  to  produce  a  semi-fluid  mass.  A  process  of  decanta- 
tion  into  vats,  or  hollows  scooped  out  below  the  surface  of  the 
ground  then  ensues,  by  which  the  unground  and  heaviest  par- 
ticles are  left  behind. 

130.  The  mixture  having  attained  the  consis- 
tency of  potter's  clay,  is  kneaded  into  balls  of   into  balls;  drying 
about  three  inches  in  diameter,  and  dried  in    f/^^^^J  caicma- 

'  tion. 

the  air  under  cover  for  about  forty-eight  hours, 

and  then  burned  in  an  ordinary  lime-kiln.  If  the  kiln  be 
perpetual,  the  drawing  may  commence  in  about  three  days, 
provided  a  white  heat  has  been  preserved  during  the  interval. 

131.  In  comparing  this  process  with  the  one  in  which  slaked 
lime  is  used,  it  w^ill  be  observed  that  they  differ  in  two  essential 
particulars,  viz. :  1st.  The  lime  mixture  must  be  thoroughly 
dried  before  burning,  wdiile  the  chalk  mixture 

need  not  be.  2d.  The  former  is  calcined  with  a  burm^og?y^first^ 
moderate  or  brig-ht  red  heat,  and  the  latter  at  a    and  second 

°  '      ^  ^  methods. 

white  heat.    The  burnt  cement  is  ground  in  the 
ordinary  way  between  millstones.    The  proportions  of  clay 
and  sand  in  the  "Portland"  cement  should,  of  course,  vary  with 
the  kind  and  quality  of  the  clay  used. 

M.  Yicat  analyzed  a  sample  from  the  manufactory  of 
Messrs.  White  &  Sons,  with  the  following  results : 

Lime  68.11 

Sihca  20.67    ^^^}5;sis  of  arti- 
ficial "Portland" 
Alumina  10.43  cement. 

Oxide  of  iron   .81 

This  composition  very  nearly  corresponds  to  that  of  the  inter- 
mediate limes. 

132.  The  following  is  a  synopsis  of  the  method  of  preparing 


90 


PEACTICAL  TBEATISE  ON  LIMES, 


artificial  cement  followed  in  England,  before  the 
Old  process.  p   ,     .  -i  i 

advantages  oi  the  intense  heat  applied  in  burn- 
ing "  Portland"  cement  were  known. 

Selection  of  the  ingredients  of  artificial  cement. — The  chalk. 
— The  white  or  upper  chalk  of  the  geologists  being  a  tolerably 

pure  carbonate  of  lime,  is  to  be  preferred  to  the 
Chalk.  .  .  1  n  -rw 

marly  or  impure  deposits  near  the  surface.  By 

mechanical  means  it  must  be  reduced  to  an  impalpable  powder, 

or,  by  the  addition  of  water,  to  a  homogeneous  paste. 

The  clay  should  be  the  hlue  alluvial  of  lakes  or  rivers,  in  a 

state  of  minute  division,  and  free  of  sand.   In  England,  the 

deposits  of  the  Medway,  and  in  the  United  States,  the  compact 

beds  of  this  unctuous  clay,  and  the  clays  used 

for  pottery,  will  answer.  A  long  exposure  to 
the  air  should  be  avoided,  as  it  has  been  found  to  injure  the 
quality  of  the  clay  for  artificial  cement. 

Proportions  of  clay  and  chalk. — By  weighty  100  pounds  of 

pure  dry  chalk  to  137|-  pounds  of  fresh  blue 
ThTInd^'ciry.       ^^^J'  ^ei^g  equivalent  to  four  of  chalk  to  five 

and  a  half  of  clay.  By  measure.^  one  cubic  foot 
of  stiff  chalk  paste  to  one  and  a  half  cubic  feet  of  fresh  blue 
clay.  ]^inety-six  pounds  of  dry  chalk  produces  one  cubic  foot 
of  chalk  paste. 

Mode  of  grinding  the  chalk. — ^The  chalk  is  ground  with  the 
water  necessary  to  produce  a  thin  paste,  in  a  mortar  mill. 
Colonel  Pasley  recommends  one  with  two  broad  vertical  iron 
wheels,  on  a  common  axle,  carried  around  by 
Sr^^^"^""^  means  of  a  vertical  shaft  connected  with  the 
axle,  and  turning  on  a  pivot  in  the  centre  of  a 
cast  iron  pan.  The  wheels  are  placed  at  unequal  distances 
from  the  centre  of  motion.  The  horizontal  axle  is  attached 
rather  loosely  to  the  shaft,  so  as  to  allow  the  wheels  to  rise  over 
lumps  that  may  be  larger  or  harder  than  usual. 

Scrapers  are  attached  to  the  vertical  shaft,  to  remove  the 
paste  from  the  circumference  and  centre  of  the  pan,  and  throw 


HYDEAULIC  CEMENTS,  AND  MOETARS.  91 


Fig.  9. 


it  in  the  track  of  the  wheels,  while  other  scrapers,  attached  to 
the  axle,  clean  the  sides  of  the  wheels,  as  they  rise  out  of  the 
paste.    The  wheels  may  be  four  and  a  half  to  five  feet  in 

diameter,  and  from  ten  to  fifteen 
inches  wide  at  the  rim  which  grinds 
the  materials,  and  one  of  them  may 
be  placed  at  the  central  distance 
of  eighteen  inches,  and  the  other  of 
twenty-four  inches  from  the  centre  of 
the  pan.  The  radius  of  the  horse- 
path may  be  eleven  feet. 

Figures  9  and  10  will  sufficiently 
explain  the  general  construction  of 
this  mill. 

After  grinding,  the  chalk  paste  will 
usually  be  found  in  too  fluid  a  state 
for  immediate  use,  and  is  generally 
allowed  to  stiffen  by  evaporation. 
The  incorporation  with  the  clay  is 
^'^S-  10.  effected  by  means  of  a  pug  mill,  and 

the  mixture  is  then  made  up  into  balls  about  two  and  a 
half  inches  in  diameter.    These  balls  are  al- 
lowed to  dry  under  cover  about  forty-eight  da/ 
hours,  or  until  sufficiently  hard  to  bear  their 
own  weight  when  piled  in  the  kiln  for  burning.     The  burning 


92 


PRACTICAL  TEEATISE  ON  LIMES, 


and  grinding  difi'er  in  no  essential  particular  from  the  process 
used  in  the  "  first  method".   (Paragraph  126.) 

133.  Hydraulic  limes  and  cements  are  artificially  manufac- 
tured in  many  localities  in  France.  The  hydraulic  lime  of  St. 
Leger  may  be  taken  as  a  type  of  the  former. 

St.  Leger  It  is  composed  of  four  measures  of  chalk  and 

hydraulic  lime.  measure  of  clay,  which  corresponds,  accord- 

ing to  the  analysis  by  Berthier,  to  eighty-four  of  carbonate  of 
lime,  and  sixteen  of  clay  containing  ten  of  silica  ;  or  in  other 

words,  one  part  of  clay  calcined  with  five  and 
chX^and^day.       ^  quarter  parts  of  pure  limestone.    The  chalk 

broken  np  into  pieces  of  the  size  of  three  or 
four  inches  cube,  is  placed  with  the  clay  in  a  large  vertical  mill 
driven  by  two  horses,  and  both  materials  are  crushed  and 
mixed  together  with  a  plentiful  supply  of  water.  The  semi 
fluid  mixture  is  then  run  off  into  a  series  of  five  troughs  placed 
on  different  levels,  in  which  it  remains  imtil  sufiiciently  stiff 
to  be  made  up  into  balls  two  to  three  inches  in  diameter. 

When  these  are  sufiiciently  dry,  they  are  cal- 
balisl^^*^°^  cined  in  an  ordinary  lime-kiln,  and  then  ground 

up  between  millstones  for  use.  The  fuel  used 
in  this  burning  is  a  mixture  of  coal  and  coke,  which  is  mingled 
with  the  balls  in  a  perpetual  kiln.  The  degree  of  heat  is  consid- 
erably below  that  required  in  burning  the  "  Portland"  cement. 

For  producing  artificial  cement,  M.  Yicat  recommends  the 
proportion  of  sixty  parts  of  clay  for  one  hundred  of  chalk,  or 
fifty-seven  of  lime. 

134.  MM.  Chatoney  and  Pivot,  Fre^ich  engineers,  recom- 
mended to  the  French  Academy  of  Sciences,  in  1856,  the  use 
of  pulverized  silica  in  combination  with  fat  lime,  for  the  pro- 
duction of  artificial  hydraulic  limes. 

Hydraulic  lime         These  gentlemen  claim  that     excellent  arti- 

composed  of         ficial  hydraulic  limes  can  be  obtained,  by  sub- 
pulverized  silica  ,  .  . 
and  fat  lime.          mitting  to  a  moderate  calcination  an  intimate 

mixture  of  nearly  pure  lime  and  very  fine  sand 


HYDEAULIC  CEMEKTS,  AND  MORTARS. 


93 


or  ground  silica,  in  the  proportion  of  twenty  to  twenty-five 
parts  of  the  pulverized  silica  to  eighty  to  seventy -five  of  lime. 
The  greater  the  care  taken  to  produce  a  homogeneous  mixture, 
the  better  will  be  the  product  obtained."  In  another  place, 
they  remark  :  "  pulverized  silica  burnt  with  fat  lime  produces 
hydraulic  lime  of  excellent  quality.  In  the  experiments  tried 
at  Havre  within  the  last  two  years,  it  has  set  under  water  in 
three  or  four  days,  and  acquired  a  hardness    r  i 

'  ^  Is  equal  or  supe- 

in  twenty-two  months  equal  and  sometimes    rior  in  hardneaa  to 

,  .11        T      t  T-t     1      T>     Portland  cement;. 

superior  to  that  attamed  oy  the  '  r^ortland 
cement  in  one  or  two  months."  The  proportions  between  the 
silica  and  lime  were  various  :  the  weight  of  the  powdered  lime 
never  exceeded  four  times,  and  was  never  less  than  one-half 
that  of  the  powdered  silica.  The  calcination  of  the  mixture 
may  be  conducted  according  to  the  directions  given  for  the 
clay  and  chalk  mixtures. 

THIRD  METHOD. 

135.  Artificial  pozzuolana  is  produced  whenever  clay  is  sub- 
jected to  a  slight  calcination.  The  properties  pos- 
sessed by  brick  or  tile  dust,  of  forming  with  fat  pozzfioJ^na. 
lime  a  mixture  possessing  hydraulic  energy,  were 

known  to  the  ancient  Romans.  Many  of  the  feebly  natural 
pozzuolanas  have  their  activity  very  sensibly  in-  „ 

^  ^  -J        J  J  Feeble  pozzuo- 

creased  by  burning,  while  there  are  many  inert  lanas  improved 
substances,  besides  the  clays  and  argillaceous 
sands  that  may  be  converted  into  artificial  pozzuolana  by  the 
application  of  a  moderate  heat.  Forge  scales,  snch  as  fall  from 
a  smith's  anvil,  the  slags  from  iron  foundries,  the  ashes  from 
under  the  grates  of  lime-kilns,  containing  cinders,  coal,  and 
lime,  are  artificial  pozzuolanas. 

136.  It  is  a  well  established  fact  that  nearly,  if  not  all,  mag- 
nesian,  argillaceous,  or  argillo-magnesian  lime- 

,  i?     1  •  1   ii  -J.'  'J.  Underburnt 

stones,  of  which  the  composition  approximates  limestones, 
to  that  of  good  cements,  however  destitute  they 


94 


PRACTICAL  TREATISE  Olf  LIMES, 


may  be  of  hydraulic  energy  and  quickness,  when  fully  cal- 
cined, are  moderately,  if  not  eminently  quick  setting,  if  suitably 
underburnt.    (See  paragraph  264  and  following.) 
The  same  is  known  to  be  the  case  with  pure  carbonate  of  lime 

when  partially  burnt.  Some  of  the  coral  sand 
Ke^  West.  ^^^^      from  Key  West,  calcined  for  half  an  hour  in  a 

crucible  at  a  bright  red  heat,  and  then  pulver- 
ized, yielded  a  paste  which  attained  a  permanent  set  under 
water  in  half  an  hour.  The  tests  of  the  strength  of  the  mortars 
thus  formed  without  sand  were  not  very  satisfactory,  as  com- 
pared with  cement  mortars.  They  were,  however,  stronger 
than  mortai-s  of  common  lime  and  sand,  besides  possessing  the 
advantage  of  sustaining  immersion  in  a  short  time  after  being 
mixed.  There  seems  no  reason  to  doubt  that  good  artificial 
Acts  as  pozzuo-  pozzuolanas  may  be  produced  by  suitably  under- 
lana  when  under-    burnine:    calcarcous   sands,  and  in  localities 

burnt.  1  .  1  ,     ,  . 

where,  or  at  times  when  cement  cannot  be  had, 
this  method  of  obtaining  hydraulic  mortar  might  be  advan 
tageously  resorted  to. 

137.  It  must  be  admitted  as  a  general  fact,  that  all  attempts 
to  utilize  the  hydraulicity  which  characterizes  underburnt 
cmnmon  lime  have  either  signally  failed,  or,  at  best,  met  with 
but  indifferent  success.  Trials  with  compound  limestones  and 
certain  mixed  earths  and  sands  have  been  more  successful. 

138.  Some  compact  dolomitic  earths  of  France  have  pro- 
duced excellent  artificial  pozzuolanas.  The  earth  is  quarried 
by  using  wooden  wedges,  inserted  and  driven  into  notches  or 
grooves  cut  in  the  beds,  in  such  a  manner  as  to  favor  the  splitting 
out  of  good  sized  masses.  These  are  divided  into  small  blocks, 
dried  in  the  sun  or  under  a  shed,  and  then  baked  in  an  ordi- 
nary lime-kiln.  For  burning,  there  is  required  about  one  mea- 
sure of  charcoal  to  sixteen  or  eighteen  measures  of  the  clay. 

139.  At  Calais,  France,  a  good  artificial  pozzuolana  is  pro- 
duced by  burning  an  argillo-calcareous  earth  taken  from  the 
sea-shore.    The  earth  is  produced  by  admixture,  from  natural 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


95 


causes,  of  the  calcareous  washings  of  the  cliffs  of  the  E^ormandy 
coast,  and  the  argillaceous  mud  either  brought  down  by  rivers, 
or  formed  by  the  crumblings  of  the  upper  bed  of  the  cliffs. 
The  earth  is  taken  from  the  beach,  dried  and  burned  in  the 
same  manner  as  the  paste  of  ordinary  clay,  in  making  artificial 
pozzuolana. 

At  Brest,  gneiss  sand  is  found  in  considerable  beds.  By 
submitting  it  to  calcination  in  a  reverberatory  furnace,  a  poz- 
zuolana is  obtained,  which,  although  not  very  energetic,  is  yet 
sufiiciently  so  to  cause  ordinary  fat  lime  mortar  to  harden 
in  seven  days. 


FOURTH  METHOD. 

140.  The  fourth  method,  not  very  well  understood  at  pres- 
ent, of  conferring  hydraulic  properties  upon  fat  lime,  is  strictly 
and  technically  artificial,  and  skives  promise  of 

.  ,  Fourth  method 

more  extensive  application  m  this  country  than    not  very  well 
either  of  those  above  noticed.    It  is,  besides,  ^^^^^stood. 
Bubservient  to  a  variety  of  useful  purposes  in  the  indus- 
trial arts,  to  which  the  others  could  have  no  possible  appli- 
cation. 

It  consists  essentially  and  briefly  in  transferring  to  the  lime 
mortar,  or  paste,  when  undergoing  the  last  manipulation  at  the 
hands  of  the  workman,  a  suitable  quantity  of  silica,  in  such  a 
minute  state  of  subdivision,  that  it  vnll  enter  into  combina- 
tion with  the  lime,  in  the  formation  of  insolu- 
ble hydro-silicate  of  lime— the  compound  to  feat^^"'^''* 
which  the  cements,  derived  from  the  argilla- 
ceous limestones,  principally  owe  the  property  of  hardening 
under  water. 

141.  The  alkalies  have  been  found  to  constitute  a  conve- 
nient and  efficacious  medium  for  this  transfer.  It  is  known 
that  if  pulverized  chalk,  or,  in  fact,  any  li  i  cMtoue  in  the  con- 


96 


TEACTICAL  TREATISE  ON  LIMES, 


dition  of  fine  powder,  be  made  into  a  paste  with  an  alkaline 
solution  of  silica,  or  what  is  commonly  known 
iifaHne^sUiiates     ^s     liquor  of  flints,"   "soluble  quartz,"  or 
ohaHi^^'^^^^^^       "  glass,"  a  chemical  decomposition  en- 

sues between  the  carbonate  of  lime  and  the 
silicate  of  potash  or  soda — the  carbonic  acid  being  transferred 
to  the  alkali,  wliilst  the  silicic  acid  (silica)  enters  into  combina- 
tion with  the  lime,  producing  silicate  of  lime.  These  reactions 
take  place  readily  under  water  ;  and  the  paste, 
undeTwater.^*^  immersed,  hardens  with  greater  or  less 

rapidity,  depending  on  the  amount  of  silica 
used,  and  comports  itself,  apparently  in  all  respects,  like  hy- 
draulic cement.  It  is,  in  fact,  an  artificial  stone,  which,  w^hen 
prepared  in  a  sufficiently  liquid  state,  and  with  the  proper 
amount  of  silica,  possesses  the  property  of  adhering  with  con- 
siderable force  to  the  surface  of  bodies  receiving  it,  constitut- 
ing a  stony  envelope,  or  covering,  as  it  were,  and  rendering 
them,  to  a  great  extent,  indestructible  by  fire  or  water.  It  is 
^  not  theoretically  or  even  practically  necessary 

need  not  be  in  that  the  alkaline  silicate  should  be  in  solution, 
solution.  when  added  to  the  lime.    If  employed  solid, 

howevw,  it  must  be  reduced  to  an  impalpable  powder,  in  or- 
der to  secure  its  thorough  and  complete  incorporation  with  the 
pulverized  carbonate,  and  the  mixture  may  then  be  formed  into 
a  paste.  Some  attempts  to  produce  artificial  hydraulic  mortar 
by  this  method  did  not  give  satisfactoiy  results. 

142.  If  the  limestone  has  been  previously  calcined,  as  will 
be  generally  the  case  in  all  preparations  of  mortar  for  mason- 
ry, whether  of  brick,  stone,  or  concrete,  and  is  in  the  condition 
of  dry  hydrate,  similar  results  may  be  ob- 

.AJ.lcdJij3.6  silicates 

mixed  with  tained  by  forming  this  hydrate  into  a  paste, 

quicklime.  ^-^-j^  ^  requisite  proportion  of  silicate  of  soda 

or  potash,  or  a  mixture  of  both,  which,  as  in  the  former  case, 
may  be  either  in  solution  or  dry  powder.  It  is  believed  that 
the  advantages  to  be  derived  from  a  thorough  and  homoge- 


HYDRAULIC  CEMENTS,  AND  MOETAES.  9Y 


neous  paste  can  be  most  readily  obtained,  when  the  silica  is 
added  in  solution. 

143.  By  the  means  just  indicated,  probably  the  common  or 
feebly  hydraulic  limes,  and  (what  in  practice  will  prove  of 
greater  importance)  the  dividing  limes  (chaux  limites  of  Yicat), 
those  which  possess  the  objectionable  and  dan- 
gerous property  of  setting  rapidly  under  water,    ^draSfc  a^d 
only  to  be  immediately  followed  by  a  gradual  intermediate 
and  complete  disintegration,  due  to  the  slug- 
gish caustic  lime  present,  may  all  be  transformed  into  reliable 
and  valuable  cements.    All  the  initial  energy  of  the  dividing 
limes  may  be  preserved  in  this  manner. 

144.  Experience  has  shown  that,  if  any  hydraulic  mortar, 
possessing  no  matter  how  high  a  degree  of  quickness  and 
energy,  be  re-pulverized  and  formed  into  a  paste,  after  hav- 
ing once  set^  it  immediately  descends  to  a  level,  in  point  of 
hydraulicity,  with  the  moderately  hydraulic  limes.  A  great 
destruction  of  the  hydraulic  principle  therefore 

results  from  any  disturbance  of  the  molecular  Sget^^desta-oys 
arrangement  of  the  mortar,  after  the  crystalli-  hydrauUc 
zation  has  commenced.    This  is  precisely  what 
takes  place  in  those  cements  denominated  intermediate  or  di- 
viding limes,  which  take  the  initial  set  promptly  and  firmly, 
but  are  subsequently  thrown  down  by  the  slaking  of  the  im- 
pure caustic  lime  which  they  contain. 

145.  The  alkaline  silicates  supply  a  specific  remedy  for  the 
defects  just  referred  to,  and  when  added  in  the  proper  form, 
and  in  sufficient  quantity,  to  cements  of  this 

type,  preserve  intact  all  their  hydraulic  power,    a  remedy 
by  presenting  to  the  defective  ingredient  an 
efficacious  neutralizing  agent.    Eight  to  ten  per  cent,  of  an 
alkaline  silicate,  of  the  consistency  of  thin  syrup,  will  confer 
upon  a  mortar  of  fat  lime  a  decree  of  hydrau- 

Ml    1        .    .      ,       ?         ^  Proportion  of 

licity  that  will  place  it  m  the  class  of  cements    alkaline  silicate 
in  hydraulic  activity,  and  any  inferior  grade  of  ^  ^® 


98 


PEACTICAL  TREATISE  ON  LIMES. 


energy  that  may  be  desired,  is  secured  by  proportionally  di- 
minishing the  percentage  of  silica.  To  elevate  the  hydraulic 
limes  to  the  standard  of  cements,  or  to  any  fixed  standard,  re- 
quires, of  course,  a  less  amount  of  silica  than  is  necessary  for 
the  common  lime,  the  proportion  varying  inversely  with  the 
active  energy  of  the  limes  acted  upon. 

146.  There  is  a  variety  of  other  important  uses  to  which  this 
silicifying  process,  as  it  may  be  termed,  can  be  advantageously 
applied,  for  our  knowledge  of  which  we  are  chiefly  indebted  to 
M.  Fred.  Kuhlmann,  Professor  of  Chemistry  at  Lille  College, 
France,  and  M.  Fuchs.  We  will  refer  to  them  very  briefly  in. 
this  connection. 

147.  When  a  solid  body,  of  any  degree  of  porosity,  is  im- 
mersed in  water  or  any  other  fluid,  it  rapidly  absorbs  a  certain 
quantity  of  the  latter,  until  the  point  of  complete  saturation  is 
reached;  and  if,  in  addition,  the  fluid  possesses  reacting  powers, 
certain  chemical  changes  will  ensue  within  the  pores  of  the 

solid  body.    If  a  porous  limestone,  like  chalk, 

Action  of  the  „  ,  .  „  i?     .  t 

silicate  on  porous  lor  example,  or  a  piece  oi  mortar  oi  lat  lime, 
^stone  or  dipped  in  a  solution  of  alkaline  silicate,  a 

certain  portion  of  the  silica  in  solution,  after  its 
absorption,  will  part  with  its  potash  or  soda,  and  enter  into 
combination  with  the  lime,  whilst  another  portion  will  remain 
mechanically  interposed  in  the  pores  of  the  solid  body,  and 
wiU,  in  time,  if  exposed  to  a  current  of  air,  solidify  by  desicca- 
tion.   The  result  will  be  that,  with  a  single  immersion,  the 

density  and  hardness  of  the  chalk  or  the  mortar 
bec^mef  harder.  ^®  augmented,  and  after  several  alternate 

immersions  and  exposures  to  the  air,  these 
properties  are  attained  in  a  considerable  degree.  The  softest 
varieties  of  chalk  may  be  thus  hardened,  so  as  to  become  capa- 
ble of  receiving  a  high  polish. 

148.  Upon  the  sulphate  of  lime  or  plaster,  the  action  of  the 
alkaline  silicate  is  essentially  the  same,  though  more  rapid, 
and  is  accompanied  by  the  inconvenience  of  giving  rise  to 


HTDKAULIC  CEMENTS,  AKD  MORTAES. 


99 


an  alkaline  sulphate,  which,  in  crystallizing    Action  of  the 

within  the  pores  of  the  solid  body,  near  the    silicate  on  the 

„         .  .         T    .      sulphate  of  lime; 

suriace,  is  apt  to  cause  disintegration.    It  is 

recommended  in  this  case  to  use  the  solution  more  diluted, 
with  a  view  to  retard  or  diminish  the  effects  of  the  crystal- 
lization of  the  sulphate,  to  such  a  degree  that  the  indurating 
solid  will  be  able  to  resist  it. 

149.  The  process  of  silicatization^  so  named  by  Mr.  Kuhl- 

mann,  which  rests  upon  the  principles  enunciated  above,  is  of 

undoubted  utility,  although,  as  yet,  its  practical  application  is 

attended  with  difficulties,  and  followed,  not  unfrequently,  with 

uncertain  results.    It  appears  destined  to  meet  with  a  varied 

and  extensive  application,  in  the  industrial  and  fine  arts,  not 

only  in  the  conversion,  at  a  moderate  cost,  of 

.  ,    1     ,      T    T         /.  .11        "  Silicatizatioa" 

common  into  hydraulic  lime  oi  any  required  de-    applicable  to  a 

gree  of  activity,  and  with  a  fair,  or  at  least,  ^^^^fjjj^  ""'^^"^ 
encouraging  degree  of  strength,  but  in  the 
preservation  of  walls  of  whatever  kind,  already  constructed 
imadvisedly  of  materials  liable  to  more  than  ordinarily  rapid 
decay,  whether  of  brick,  stone,  pise,  or  concrete ;  in  the  restora- 
tion and  conservation  of  statuary,  monuments,  architectural 
ornaments,  &c. ;  in  transforming  designs  cast  in  ordinary  plas- 
ter into  hard  and  durable  stone,  in  rendering  wood- work,  and, 
to  a  limited  extent,  even  cloth  fabrics  indestructible  by  fire, 
and  in  a  multitude  of  other  collateral  uses,  some  of  which  are 
even  now  well  developed  and  in  practical  operation,  while 
others  remain  still  in  their  infancy,  giving  more  or  less  encour- 
aging promises  of  future  utility  and  value. 

150.  Within  the  last  ten  years,  grave  doubts  have  arisen 
among  European  engineers,  as  to  the  suitability 

«  , ,  •  1         .  J  -u        •  •         Doubts  of  the 

ot  those  artincial  mortars  prepared  by  mixing    stability  of  artifi- 

slightly-burnt  clay  with  common  limo,  for  con-  rortShe"«. 

structions  exposed  to  the  action  of  sea-water. 

The  French  engineers  had  entertained  very  favorable  opinions 

of  those  mortars,  and  had  paid  great  attention  to  their  use 


100 


PRACTICAL  TEEATISE  ON  LIMES, 


between  the  years  1820  and  1840,  deriving  their  opinions 
mainly  from  the  investigations  of  MM.  Yicat, 

Authority  for  Treussart,  Eancourt,  and  others,  who  thouajht 
using  them.  .  '  ^ 

themselves  justified  in  deducing  from  their  re- 
sults that  the  clays,  when  subjected  to  the  proper  degree  of 
calcination,  would  operate  in  expediting  the  hardening  of  lime, 
in  all  respects  like  the  natural  pozzuolanas.  For  some  years, 
these  mortars  exhibited  no  marks  of  weakness  or  instability, 
but  more  recently  have,  according  to  the  opinion  of  MM. 
Chatoney  and  Rivot,  so  far  yielded  to  the  solvent  action  of  sea- 
water  in  some  localities,  that  but  few  constructors  would  be 
justified  in  using  them,  until  their  peculiarities  are  further 
developed  by  experiments  and  the  test  of  time.  The  mortars 
Natural  pozzuo-  derived  from  a  mixture  of  natural  pozzuolana 
lana  mortars  give    and  fat  lime  have  been  found  to  give  better  re- 

better  results 

suits,  although  it  is  conceded  by  many  who 
have  advocated  the  preparation  of  hydraulic  mortar  by  this 
method,  that  the  Romans  were  more  successful  in  the  employ- 
ment of  natural  pozzuolana  than  those  engineers  who  have 
given  attention  to  this  subject  during  the  present  century. 

161.  Marshal  Yaillant,  member  and  reporter  of  a  commission 
of  the  Academy  of  Sciences  of  France,  to  whom  was  referred 
a  memoir  of  MM.  Chatoney  and  Rivot,  entitled,  "  General 
Considerations  upon  Hydraulic  Materials  used  for  Constructions 

in  the  Ocean,"  submitted  to  the  Academy  in  the 
SfiTamantttiere-  year  1856,  says  in  his  report,  when  speaking  of 
or^iencts'^'^^'^^    mortars  of  lime  and  pozzuolana:  '^Natural 

pozzuolana  mortars  were  used  by  the  Romans 

for  submarine  constructions,  which  are,  at  the  present  day,  in 

a  perfect  state  of  preservation.    The  Dutch  engineers  have 

likewise  used  them  successfully  in  their  sluice  works.    But  all 

, .  ,    .^^    recent  trials  with  pozzuolana,  natural  or  artifi- 
Recent  tnals  with  . 

pozzuolana  unsuc-  cial,  have  resulted  in  failures.  According  to 
cessfui.  MM.  Chatoney  and  Rivot,  these  mistakes  in  the 

use  of  pozzuolana  could,  without  doubt,  have  been  avoided  if, 


HYDEAULIO  CEMENTS,  AND  MOETAES.  101 


in  conformity  to  the  usages  of  the  ancients,  they  had  been  pre- 
viously submitted  to  a  long  concoction.  Those  gentlemen  have 
as  yet,  no  experimental  results  to  furnish  in  support  of  this 
assertion,  but  it  appears  very  rational.  We  can  comprehend, 
in  fact,  that  if  the  previous  concoction  is  advantageous  to  mor- 
tars of  lime,  and  even  of  cement,  it  is  indispensable  to  the 
success  of  mortars  of  pozzuolana,  which  differ  from  the  former, 
in  that  the  combinations  of  the  lime  with  the  silica  exist,  for 
the  limes  and  cements,  already  formed  by  the  calcination,  and 
have  only  to  become  hydrated  at  the  time  of  their  use ;  whilst, 
in  the  fabrication  of  mortars  of  pozzuolana,  the  silica  and  alum- 
ina have  to  free  themselves  from  combinations  in  which  they 
exist  in  the  pozzuolana,  in  order  to  form  with  the  lime,  in  the 
wet  way,  those  compositions  which  form  hy- 
drates under  water.  We  see  from  this,  that  it  cltin'S'Id!'''' 
is  better  to  mix  pozzuolana  with  fat  lime  than 
with  hydraulic  lime,  since  in  the  latter  case,  the  hydraulic  com- 
positions formed  in  the  dry  way  (voie  seche)  during  the  calci- 
nation, will  have  set  a  long  time  before  those  formed  in  the  wet 
way  {voie  humide)  become  hydrates,  and  the  setting  of  these 
latter  might  endanger  the  stability  of  the  mortars  by  disinte- 
gration." Moreover,  in  mortars  of  natural  pozzuolana  and 
hydraulic  lime,  it  is  only  the  excess  of  caustic  lime  contained 
in  the  latter,  which  combines  advantageously  with  the  silica 
and  alumina  of  the  pozzuolana.  The  report  goes  on  to  say : 
"  The  artificial  pozzuolanas  consist  of  burnt  clay  pulverized ; 
most  of  them  contain  lime,  and  possess  the  same  causes  of  de- 
struction as  the  mortars  of  natural  pozzuolana  and  hydraulic 
lime.  They  have  not  yet  been  successful  in  the  ocean,  and 
their  employment  will  always  be  attended  with  difficulty, 
principally  on  account  of  the  irregularity  of  the  mortars  into 
which  they  are  introduced. 

"  The  authors  have  had  in  view,  in  their  memoir,  only  those 
mortars  exposed  to  the  action  of  sea-water,  but  they  entertain 
the  opinion  that  most  of  these  observations  are  applicable  to 


102 


PE ACTIO AL  TREATISE  ON  LIMES, 


mortars  immersed  in  fresh  water.  Scarcely  ten  years  have 
elapsed  since  the  disintegration  of  mortars  by  the  action  of  sea- 
water  became  a  well-established  fact.  It  was  not  observed  until 
after  the  time  when  a  too  absolute  confidence  in 
continued!^^  hydraulic  materials,  led  to  the  execution  of  heton 
(concrete)  masonry  in  immediate  contact  with 
water,  without  any  revetment  of  cut  stone  or  carpentry,  with- 
out any  covering  of  wood,  and  without  any  of  the  protections 
which  the  ancient  works  received.  It  is  also  but  a  short  time 
since  heton  has  been  placed  in  contact  with  currents  of  fresh 
water,  and  although  alterations  have  not,  as  yet,  taken  place  in 
that  kind  of  masonry,  nevertheless,  it  may  be  presumed  that 
they  are  gradually  produced  by  the  dissolving  action  of  the  gas, 
and  the  salts  which  the  water  contains,  modified  by  the  tern 
perature,  and  the  action  of  the  tides." 

152.  The  proposition  laid  down  by  MM.  Chatoney  and 
Rivot,  that  the  mortars  of  Italian  mzzuolana. 

Opinion  of  MM.  '  _       ,  .     .7  7.,  , 

Chatoney,  and       recentiy  employed  m  the  Mediterranean^  ham 
given  unsatisfactory  results^  is  concurred  in 
substantially  by  M.  Tostain,  Inspector-General  of  Eoads  and 
, .  ,        Bridges,  who,  in  his  letters  written  subsequently 

concurred  in  by  &    3         ?  1  j 

Inspector-Gen-  to  his  inspections  in  the  years  1857  and  1858, 
wherein  his  attention  had  been  specially  di- 
rected to  the  condition  of  the  mortars  and  concretes,  observes : 
"  I  have  said,  and  shall  again  say,  that  I  saw  in  all  the  ports 
which  I  visited  on  the  Mediterranean,  in  France,  Algeria,  Cor 
sica,  and  on  the  coast  of  Italy,  pozzuolana  mortars  attacked  by 
sea-water.  I  do  not  say  absolutely  that  all  the  mortars,  with- 
out exception,  were  altered.  There  were,  no  doubt,  good 
portions  on  which  I  saw  nothing  wrong ;  but  everywhere,  that 
is,  at  all  the  ports,  I  found  partial  alterations.  On  the  other 
hand,  I  have  not  examined  the  walls  of  Dock  JSTo.  3,  mentioned 
by  Mr.  Noel.* 

"  With  regard  to  the  portions  exposed  to  the  shock  of  heavy 
*  The  dock  referred  to  is  in  the  harbor  of  Toulon. 


HYDRAULIC  CEMENTS,  AND  MOETAHS. 


103 


seas,  such  as  the  large  blocks  of  the  outside  works  of  the  break- 
water, I  shall  go  further,  and  state  that  I  have  not  seen  a 
single  one  that  was  free  from  alterations,  that  is,  one  whose 
whole  surface  was  intact  and  well  preserved.  The  surface  be- 
comes rough  at  first,  and  is  continuously  made  more  so  by  the 
waves ;  the  pebbles  of  the  beton  are  left  projecting  and  after- 
wards get  loose ;  the  edges  of  the  work  get  blunt,  and  the 
volume  of  the  block  gradually  decreases." 

153.  On  the  other  hand,  M.  E^oel,  Inspector-General  of 
Roads  and  Bridges,  who  takes  the  other  side  of 

.  IT         .  .  Contrary  opinion 

the  question,  brmgs  to  the  discussion  a  ripe  ex-  of  inspector-Gen- 
perience,  and  a  reputation  by  no  means  second  ^^^^ 
to  that  of  M.  Tostain.  In  reference  to  the  alleged  failure  of 
mortars  of  fat  lime  and  Italian  pozzuolana,  he  says:  "This 
assertion  is  in  contradiction  of  well-established  facts.  All  the 
hydraulic  works  at  the  port  of  Toulon,  have  been  executed  ex- 
clusively, even  of  late  years,  with  mortars  composed  of  Italian 
pozzuolana  and  lime,  either  fat  or  hydraulic  (that  of  Lagoubran), 
and  I  affirm  with  all  the  authority  which  a  thirty  years'  resi- 
dence at  this  port  can  confer,  that  not  one  of  the  works  has 
failed  on  account  of  defective  mortar."  M.  Noel  also  refers  to 
the  successful  use  of  the  same  kind  of  mortar  by  Colonel  Sauli, 
in  the  construction  of  the  dry  dock  at  Genoa,  where  it  was  used 
as  concrete.  A  description  of  this  dock  in  the  "  Annales  des 
Fonts  et  Chaussees,"  for  1853,  furnishes  the  following  extract : 
"  If  the  work  is  examined  more  in  detail,  it  is  found  that  the 
heton  (concrete)  which  constitutes  the  bottom  of  the  apron  and 
the  exterior  surface  of  the  side  walls,  has  acquired  a  very  great 
hardness  in  consequence  of  its  composition, (pozzuolana  of  Rome, 
ordinary  lime,  and  calcareous  gravel),  and  that  it  is  free  from 
all  porosity,  in  consequence  of  the  care  which  the  skilful  di- 
rector of  these  works  took  to  clear  his  beton,  by  constantly 
pumping  up  the  washings  (laitance)  during  the  operation  of 
immersion." 

154.  The  mole  of  Algiers  was  executed  in  concrete,  some 


104 


PEACTICAL  TREATISE  ON  LIMES, 


portions  of  which  were  composed  of  artificial  blocks,  allowed  to 
dry  in  the  air  before  immersion,  and  other  portions,  of  concrete 
immersed  fresh.  In  this  connection,  therefore,  we  will  briefly 
refer  to  certain  "  observations  and  experiments  upon  the  mortars 
Mortars  of  the  employed  in  the  sea  at  Algiers,"  made  by  M. 
mole  of  Algiers.  Ravier,  engineer  of  roads  and  bridges,  and  pub- 
lished in  the  "  Annales  des  Fonts  et  Chaussees,"  vol.  viii.,  1854. 
From  this  we  learn  that  prior  to  the  year  1852,  the  mortars 
immersed,  after  drying  in  the  air,  were  composed  of  fat  lime 
and  a  mixture  of  equal  parts  of  sand  and  Roman  pozzuolana,  and 
that  the  lime  was  slaked  successively  by  the  ordinary  process, 
and  by  aspersion.  In  the  first  case,  the  mortar  contained  equal 
volumes  of  lime  paste,  sand,  and  pozzuolana,  in  the  second  2J 
volumes  of  slaked  lime  in  powder,  1-J  of  sand,  and  1^  of  pozzu- 
olana. Mortars  for  immediate  immersion  were  composed  of  fat 
lime  and  Roman  pozzuolana  in  various  proportions.  Since  the 
beginning  of  the  year  1852,  hydraulic  lime  from  Theil,  on  the 
right  bank  of  the  river  Rhone  has  been  used,  the  stone  being 
calcined  at  Algiers,  and  slaked  by  aspersion,  as  required  for 
use.  For  making  the  mortar  for  the  artificial  blocks,  it  is 
mixed  with  sand.  In  exceptional  cases,  when  the  blocks  are 
to  be  immersed  at  the  age  of  thirty  days,  one-half  of  the  sand  is 
replaced  by  pozzuolana.  An  analysis  of  the  Theil  limestones 
is  given  in  Table  lY.  Page  226. 

155.  "Without  attempting  a  connected  synopsis  of  M.  Ra- 
vier's  report,  referred  to  in  the  last  paragraph,  a  few  brief 
extracts  are  given  below  : 

1st.  Page  25  :  "  It  results  from  the  foregoing  experiments, 
that  all  mortars  on  trial  of  fat  lime,  sand,  and  Roman  pozzuo- 
^  ^    ^  ^  lana,  after  dryinp*  in  the  air,  or  immersion  in 

Extracts  from  M.  '  ./to  ' 

Ravier's  report  fresh  water,  are  destroyed  when  placed  in  sea- 
thereon.  water.    This  takes  place  even  with  a  mortar 

containing  by  weight  about  twenty  of  caustic  lime  for  one  hun- 
dred of  pozzuolana,  and  one  hundred  and  thirty  of  sand." 
2d.  Page  29 :  "  It  follows  from  these  observations  that  fat 


HYDEAULIC  CEMENTS,  AND  MORTAES. 


10 


lime  mortars  do  not  sustain  immediate  immersion  (in  sea 
water)  no  matter  what  proportion  of  pozzuolana  they  con- 
tain "  a  r^^Q  trials  were  all  favorable  to  mor- 
tars of  hydraulic  lime  with  or  without  pozzuolana." 

3d.  The  trials  with  mortars  of  fat  lime  and  Grenoble  cement 
allowed  to  dry  in  the  air,  show  that  the  cohesion  of  these 
gangs  diminishes  w^th  age.    A  mortar  composed  by  volume  of 

2.15  of  fat  lime,  1.00  of  cement,  and  5.40  of  sand  (correspond- 
ing with  equal  weights  of  dry  cement  and  quicklime)  gave  a 
cohesion  strength  of  2.55  killograms  per  centi- 
metre square,  at  the  age  of  two  months,  and  of  fain^ortars?^^" 

1.16  killograms  at  the  age  of  twenty  months. 

Another  mortar,  with  the  same  proportion  of  sand,  with  a  gang 
containing  by  weight  100  of  dry  cement  and  47  of  quicklime, 
gave  at  the  same  ages,  breaking  weights,  2.82  kilos,  and  1.59 
kilos,  per  centimetre  square,  respectively. 

156.  The  following  is  a  condensed  view  of  the  resume  given 
by  M.  Ravier  himself : 

1st.  The  Roman  pozzuolanas  used  at  Algiers  are,  contrary 
to  the  opinion  hitherto  entertained,  incapable  of  forming  with 
fat  limes,  mortars  able  to  resist  the  saline  action  of  the  sea- 
water. 

2d.  The  form  of  the  mortars  submitted  to  immersion 
exerts  an  important  influence  upon  the  action  of  the  sea- 
water;  the  sharp  edffes  and  curves  of  small  „ 

,  ,  ,  M.  Ravier's 

radius  assist  the  destructive  action ;  plane  sur-    condeiised  re- 
faces,  OR  the  contrary,  essentially  protect  the 
cohesion  of  the  mortars,  and  may  preserve  them  unaltered  for 
several  years. 

3d.  Tl^e  preservation  of  the  works  executed  at  Algiers 
with  fat  lime  and  Roman  pozzuolana,  is  specially  due  to  the 
deposits  of  mineral  substances  secreted  by  marine  animals. 

4th.  In  this  respect,  the  artificial  development  of  beds  of 
oysters  upon  sea  works,  appears  to  promise  important  results. 

5th.  Mortars  of  fat  lime  and  l^aples  or  Rachgoun  pozzuo- 


106 


PRACTICAL  TREATISE  ON  LIMES, 


lana,  also  fail  in  the  sea.  Similar  failure  attaches  to  the  mor 
tars  of  sand  and  St.  Chamas  hydraulic  lime. 

6th.  All  the  observations  are  favorable  to  the  perfect  pres- 
ervation in  sea-water  of  mortars  of  sand  and  hydraulic  lime 
horn  the  Theil  quarries. 

7th.  The  substitution  of  an  equal  volume  of  Rachgoun  or 
Eonian  pozzuolana  for  a  part  or  the  whole  of 
tinuecT^^'  ^^^*  "^^^  sand,  in  the  mortal's  of  Theil  hydraulic 
lime  disposes  them  unfavorably  at  first,  to  re- 
sist the  saline  action.  The  phenomena  of  disaggregation  that 
were  observed  were  limited,  and  furnish  no  sufiicient  reason, 
without  further  proof,  for  excluding  the  use  of  pozzuolana  con- 
currently with  hydraulic  limes,  when  it  is  desirable  or  neces- 
sary to  obtain  a  mortar  that  will  indurate  rapidly. 

8th.  The  Roman,  Rachgoun,  and  Naples  pozzuolanas  used 
in  the  trials,  are  not  homogeneous ;  the  differences  afi:ecting 
the  composition  of  the  silicate  of  alumina,  in  each  of  these 
materials,  vary  between  somewhat  wide  limits. 

9th.  The  same  want  of  liomogeneousness  is  established  for 
the  limestones  of  the  Theil  and  Alignol  quarries,  which  both 
belong  to  the  same  formation. 

10th.  The  analysis  of  the  limestones  of  the  Theil  quarry, 
and  the  results  obtained  in  the  sea  with  the  limes  manufac- 
tured from  them  show,  that  by  taking  for  the  measure  of  re- 
sistance to  the  saline  action,  the  ratio  of  the  clay  plus  the 
magnesia  to  the  lime,  this  ratio,  which  has  been  called  the 
index  of  hydrcmlicity,  can,  on  the  average  fall  to  without 
the  mortars  being  destroyed,  whether  they  were  immersed  dry 
or  fresh. 

11th.  The  disaggregation  of  the  mortars  coincides  with  the 
increase  in  the  quantity  of  the  sulphate  of  lime, 
U^ueT""^'  ^®  attributed  to  that  salt,  produced  by 

the  action  upon  the  lime,  of  the  sulphate  of 
magnesia  of  the  sea-water.  It  was  produced  in  variable  pro- 
portions in  all  the  gangs  experimented  upon,  but  destroys 


HYDRAULIC  CEMEOTS,  AND  MORTAES.  107 


them  only  in  the  cases  when  it  is  produced  in  sufficient  quan- 
tities. The  surfaces  upon  which  this  salt  exists  abundantly, 
can  acquire  and  preserve  a  considerable  hardness. 

12th.  In  the  mortars  of  fat  lime  and  Roman  pozzuolana, 
the  sea-water  attacks  not  only  the  free  lime,  but  also  that  com- 
bined with  the  silica. 

13th.  In  the  mortars  of  hydraulic  lime  preserved  intact, 
after  having  been  kept  under  water  for  several  years,  and  also 
in  the  gangs  of  Yassy  cement,  a  notable  proportion  of  free 
lime  is  detected. 

157.  M.  Feburier,  as  the  result  of  numerous  experiments  at 
St.  Malo  upon  various  limes,  pozzuolanas  (nat-  Feburier's 
ural  and  artificial),  and  trass,  arrives  at  the  fol-  experiments, 
lowing  conclusions,  which,  although  indorsed  by  M.  Yicat, 
are  by  no  means  coincident  with  the  deductions  of  other  emi- 
aent  French  engineers : 

1st.  "  That  mortars  of  fat  lime  and  Dutch  trass  do  not  resist 
the  action  of  sea-water." 

2d.  "  That  ordinary  artificial  hydraulic  limes,  or  natural  feebly 
hydraulic  limes,  even  when  mixed  with  feebly  hydraulic  poz- 
zuolanas, equally  do  not  resist." 

3d.  "The  only  limes  capable  of  thus  resisting  are  the  ^  twice 
kilned'  artificial  hydraulic  limes,  or  the  natural 

His  conclusions 

hydraulic  limes  which  approach  the  limits  of 
cements." 

These  conclusions  are  irreconcilable  with  the  excellent  re- 
sults obtained  by  the  Dutch  engineers  with  mixtures  of  rich 
shell-lime,  trass,  and  sand. 

158.  There  seems  no  reason  to  doubt  that  the  natural  quick- 
setting  cements,  such  as  the  Roman,  the  Yassy,  the  Rosendale, 
and  the  Boulogne  "Portland"  brands,  and  those  artificial 
Portland  cements,  produced  by  calcining  a  mixture  of  chalk 
and  clay  with  a  heat  sufficiently  great  to  produce  incipient 
vitrification,  can  furnish  mortars  capable  of  resisting  the  sol- 
vent action  of  sea-water. 


108 


PRACTICAL  TREATISE  ON  LIMES, 


159.  Upon  the  general  question  of  the  destructive  effects  of 
Bea-water  upon  those  gangs,  natural  or  artificial,  which  form 
the  bases  of  hydraulic  mortars,  whether  derived  from  hy- 
draulic lime,  cement,  or  pozzuolana,  M.  Yicat's  researches  led 
him  to  certain  conclusions  which  may  be  condensed  as  follows, 
from  the  "Annales  des  Fonts  et  Chaussees"  for  1854: : 

1st.  The  double  hydro-silicates  of  alumina  and  lime  are  de- 
void of  stability,  and  will,  without  exception,  if  pulverized  and 

„  ,  .  immersed  in  sea-water,  or  even  pure  water,  be- 
M.  Vicat's  views.  t       ,         ,  ,  . 

lore  they  have  been  subjected  to  the  action  of 

carbonic  acid,  and  thereby  transformed  to  carbonates,  give  up 

to  the  water  an  appreciable  quantity  of  lime. 

2d.  The  other  conditions  remaining  the  same,  a  dilute  solu- 
tion of  sulphate  of  magnesia  substituted  for  the  jpure  water, 
will  convert  all  the  lime  of  these  silicates  into  a  sulphate,  un- 
less carbonic  acid  be  present  during  the  reaction,  in  which  case 
its  equivalent  of  lime  will  become  a  carbonate. 

3d,  All  pozzuolanas,  irrespective  of  origin  or  comjDOsition, 
require  for  their  complete  practical  saturation  a  much  smaller 
dose  of  lime  than  they  generally  receive,  when  made  into 
mortar,  owing  to  imperfect  pulverization  and  manipulation. 

4th.  The  afiinity  of  carbonic  acid  for  the  lime  is  sufficiently 
powerful,  in  the  presence  of  water,  to  separate  its  full  equiva- 
lent of  lime  from  combination  with  the  other 
ingredients  of  these  silicates,  leaving  the  said 
ingredients,  whether  combined  or  not  with  each  other,  simply 
mixed  mechanically  in  the  compound. 

160.  From  the  foregoing  it  would  appear  that  sea- water 

will  destroy  the  gangs  of  all  mortars  derived 
Protecting  coat.  '  •    t     .    i  i       n  i 

from  the  sources  indicated,  ii  it  be  allowed  to 
penetrate  the  immersed  masses ;  but  as  some  mortars  do  prac- 
tically withstand  continuous  immersion  in  sea-water,  it  fol- 
lows that  the  latter  meets  on  the  surface  something  to  impede 
or  prevent  its  penetrations.    These  impediments  are  : 

1st,  and  principally,  a  coating  of  carbonate  of  lime ;  the  car- 


HYDEAULIC  CEMENTS,  AND  MOETAES. 


109 


bonic  acid  being  sri])plied  from  the  atmosphere  befcre  immer- 
sion, and  subsequently  from  the  water ;  ^  , 

^  ^         ./  .         ,        .  ,  Carbonate  of  lime. 

2d,  in  certain  cases,  particularly  with  gangs 

derived  from  the  ma^nesian  limestones,  the  for-    Carbonate  of  mag. 

°  ,  nesia. 

mation  of  carbonate  of  magnesia. 

3d,  an  incrustation  of  shells  and  submarine  vegetation. 

161.  M.  Yicat  was  subsequently  led  to  recommend  mag- 
nesia as  a  suitable  ingredient  of  mortars  to  be    Magnesia  re- 
immersed  in  sea-water,  stating  that  if  it  could  commendfid. 

be  obtained  at  a  cost  that  would  permit  its  application  to  such 
purposes,  "  the  problem  of  making  heton  (concrete)  unaltera- 
ble by  sea-water  would  be  solved."  That  learned  experi- 
menter also  intimates  that  the  Theil  hydraulic  lime  is  the  only 
one  with  which  he  is  acquainted,  that  could  unquestionably 
furnish  a  mortar  indestructible  by  sea-water,  suggestion  by 
AJ.  Balard  suggests  that  the  mother  water  of  ^-  ^alard. 
salt  ponds,  applicable  to  no  other  useful  purpose,  might  sup- 
ply magnesia  at  a  moderate  cost. 

162.  In  the  presence  of  these  conflicting  opinions,  which 
are  characterized  by  apparently  irreconcilable  elements,  the 
American  engineer  can  congratulate  himself  that  the  supply 
of  hydraulic  cement  in  this  country  affords  a  American  ce- 
more  reliable  source  of  hydraulic  mortars  than  "^^"^^  mortars, 
either  natural  or  artificial  pozzuolana  ;  and  that  this  question, 
therefore,  possesses  for  him  no  important  practical  bearing. 


110 


PEACTICAL  TEEATISE  ON  LIMES 


CHAPTER  Y. 

163.  Our  nomenclature  of  the  products  derived  from  the 
calcinations  of  the  several  varieties  of  limestone,  still  remains 
imperfect. 

164.  These  products  are  as  varied  and  diversified  in  their 

character,  and  require  as  many  distinct  and  peculiar  modes  of 

,   ,       manipulation,  in  order  to  satisfy  the  conditions 
Diversified  char-  ' 

acterofiime-  which  are  indispensable  to  their  advantageous 
Btones.  employment  for  mortar,  as  there  are  variations 

in  the  composition  of  the  limestones  themselves.  This  is  more 
especially  the  case  with  those  limestones  which  contain  so  large 
an  amount  of  foreign  matter,  such  as  silica,  alumina,  magnesia, 
etc.,  usually  exceeding  ten  of  the  whole,  as  to  disqualify  them 
for  ordinary  use  as  fat  lime,  but  which  places  them  in  the  cate- 
gory of  hydraulic  limes  or  cements.  When  we  keep  in  view  the 
multiplicity  of  causes  for  such  variation  in  all  sedimentary  rocks, 
causes,  indeed,  that  pertain  in  their  fullest  force  to  all  calca- 
reous formations,  and  more  especially  to  those  which,  from 
their  compound  character,  have  proved  to  be  best  adapted  to 
the  production  of  hydraulic  mixtures,  we  obviously  need  seek 
no  further  for  an  explanation  of  that  remarkable  want  of  homo- 
geneousness  which  characterizes  these  deposits,  or  expect  to 
find  any  locality  in  which  it  does  not  exhibit  itself. 

165.  The  same  strata,  even  within  very  narrow  lateral  limits, 
frequently  become  so  changed  in  their  physical  appearance  as 
well  as  in  their  chemical  composition,  as  to  lose  not  only  the 
means  of  verifying  their  geological  identity,  but  their  most 
prominent  lithological  features. 


HYDRAULIC  CEMENTS,  AND  MORTAES.  Ill 


166.  We  miglit,  therefore,  expect  that  the  best  practical  rales 
for  converting  such  heterogenoeus  material  into  use  as  a  gang 
for  mortar,  would  require  to  be  modified  to  suit  local  circum- 
stances. It  is  equally  self-evident  that  such  modifications  can 
only  be  properly  determined  by  adequate  pre-  j^ocai  examina- 
liininary  and  local  tests.  Although  the  theoret-  tio^s  and  testa 
ical  correctness  of  these  premises  will  perhaps  ^ 

be  questioned  by  very  few,  their  practical  observance  by  manu- 
facturers and  consumers  of  limes  and  cements,  is  greatly  neg- 
lected. 

167.  The  calcareous  deposits  in  the  United  States,  from  which 
the  present  supplies  of  lime  and  cement  are  derived,  if  severally 
classified  and  arranged  according  to  their  composition,  as  shown 
by  quantitative  analyses,  would  strikingly  illustrate  the  necessity 
of  awarding  to  each  locality  such  special  rules  for  manipulation 
as  can  only  be  supplied  by  an  extended  series  of  experiments. 
It  is  not  to  the  almost  endless  variety  of  quarries  of  dissimilar 
stone  simply,  tliat  the  difficulty  is  confined,  since  this,  however 
great,  is  only  coextensive  with  the  extraordinary  heterogeneity 
generally  existing  among  the  strata  of  the  same  quarry.  Al- 
though this  feature  does  not  characterize  the  beds 

of  common  limestone,  at  least,  not  to  an  extent  ^meri?depo^ts^ 
that  can  be  regarded  as  prominent,  it  is  so  uni- 
formly present  in  the  argillo-magnesian  deposits,  that  we  may 
safely  assume  that  every  extensive  deposit  capable  of  furnish- 
ing an  energetic  cement,  will  also  furnish  from  among  its  several 
layers,  every  inferior  grade  of  combination,  down  to  slightly 
hydraulic,  meagre,  and  common  lime. 

168.  Frequently,  and  perhaps  generally,  among  deposits  fur 
nishing  cement  stone,  the  several  lay ers— which  vary  consider- 
ably in  thickness,  though  they  are  seldom  less  than  one  foot  or 
more  than  six — so  far  preserve  the  character  and  relative  pro- 
portion of  their  constituent  parts  within  the  ordinary  lateral 
limits  of  a  single  quarry,  as  to  require  only  an  occasional, — it 
may  be  a  semi-weekly,  or  weekly,  or  perhaps,  in  rare  cases,  a 


112 


PRACTICAL  TREATISE  ON  LIMES, 


montlilj, — verification  of  their  respective  characters,  but  in  a 
majority  of  cases,  the  v^^ant  of  homogeneousness 
^stenrfi'L^''"  extends  to  the  several  layers  individually,  and 
attaches  to  them  persistently  for  miles  in  ex- 
tent, rendering  it  necessary  to  keep  a  daily,  and  even  hourly 
surveillance  upon  the  workmen,  to  prevent  their  making  use  of 
bad  or  worthless  stone. 

169.  When  the  stone  occurs  in  distinct  and  easily  recognized 
layers  which,  for  considerable  distances,  retain  with  little  vari- 
ation, a  known  and  specific  character,  whether  good,  bad,  or 
doubtful,  and  which  are  readily  separated  from  each  other  along 
the  principal  planes  of  subdivision,  the  practical  difficulties  to 
be  overcome  in  quarrying  are  comparatively  few,  and  simply 
require  for  their  removal,  the  employment  of  reliable  and  faith- 
ful workmen,  who  will  exercise  the  precaution  to  reject  those 
strata  which  are  known  to  be  unfit  for  use. 

170.  In  the  general  case,  however,  the  problem  is  far  less 
easy  of  solution,  for  we  find  those  materials,  whose  exclusion 
from  the  combination  is  of  the  highest  importance,  disseminated 
throughout  a  series  of  strata,  in  constantly  and  widely  varying 
Practical  d  ffic  1  Proportions,  and  frequently  in  a  form  present- 
ties  in  selecting  ing  no  physical  features  except  to  the  most 
good  stone.  practiced  eye,  to  assist  in  their  detection.  The 
calcination  sometimes  so  far  alters  their  appearance,  as  to  ren- 
der them  more  easily  identified.  These  materials  generally 
consist  of  carbonate  of  lime  more  or  less  pure ;  or  a  compound 
stone,  in  which  the  preponderating  ingredient  is  inert  silicious 
sand ;  or  argillaceous  slate  or  limestone,  containing  an  excess 
of  clay  and  granulated  silica.  They  usually  occur  in  rather 
thin  masses  or  sheets,  varying  from  two  or  three  inches  to  sev- 
eral feet  in  length  and  breadth.  There  is  probably  not  a  single 
quarry  in  the  United  States,  worked  for  hydraulic  lime  or  ce- 
The  ordinary  pre-  entirely  free  from  them.  For  the  detec- 
cautions  neces-      tion  and  exclusion  of  these  objectionable  por- 

gary. 

tions  of  a  quarry,  we  must,  therefore,  depend 


HYDRAULIC  CEMENTS,  AND  MOETAES.  118 


conjointly  npon  tlie  faithfulness  of  tlie  quarryman,  the  experi- 
ence of  the  burner,  and  his  skill  in  detecting  them  after  calci- 
nation. 

171.  Changes  in  the  character  of  a  cement  stone  often  take 
I  lace  slowly  and  progressively  within  the  limits  of  individual 
beds,  in  directions  both  perpendicular  and  parallel  to  the  planes 
of  stratification,  without  any  perceptible  variation  in  the  ap- 
pearance of  the  stone,  or  in  its  homogeneousness,  and  simply 
require  for  their  correction  a  modification  in  either  the  propor- 
tion of  the  difiPerent  layers  introduced  into  the  combination,  in 
the  degree  of  calcination  to  which  they  are  subjected,  or  in  both. 
It  might,  under  such  circumstances,  become  necessary  to  use 
separate  kilns  for  layers  that  had  pireviously  been  mixed  to- 
gether in  burning.    Deposits  of  this  character 

require  close  and  constant  attention,  in  order    dSsTmUar  stone, 
that  the  proportion  of  the  several  dissimilar 
layers,  and  the  intensity  and  duration  of  the  heat  employed 
in  burning  them,  may  be  so  regulated  as  to  give  results  that 
shall  be  uniform,  or  at  least  approximately  so. 

172.  It  is  therefore  important  that  some  practical  method  of 
ascertaining  the  absolute  ^s  well  as  the  relative  value  of  these 
several  kinds  of  stone,  should  be  pointed  out, 

and  it  is  equally  important  that  such  a  method  fectmiSel'^^^ 
should  be  simple,  inexpensive,  and  easy  of  ap- 
plication. It  is  not  necessary,  though  it  might  be  advanta- 
geous in  some  cases,  that  it  should  comprise  any  essay  upon 
the  composition  of  the  stone,  or  the  proportion  of  its  constituent 
parts.  Indeed,  any  practical  method  would  be  much  better 
without  any  accessory  requiring  the  exercise  of  any  theoretical 
knowledge,  not  within  the  ready  comprehension  of  that  class 
of  men  to  whom  manufacturers,  with  few  exceptions,  confide 
the  details  of  their  work,  and  consequently  not  susceptible  of 
daily  and  hourly  application  by  them. 

173.  The  only  apparatus  required  for  this  purpose  is  a  cruci- 
ble of  the  capacity  of  one  pint  or  thereabouts,  and  a  mortar  and 

8 


114 


PRACTICAL  TEEATISE  ON  LIMES, 


pestle.  The  crucible  should  be  perforated  near  the  bottom,  in 
several  places,  to  give  an  upward  current  of  air  and  facilitate  the 

escape  of  carbonic  acid  gas,  and  should  be  pro- 
chtr1!cter!^^^      vided  with  a  cover  Hkewise  perforated.  When 

access  can  be  had  to  a  grate  fire  of  anthracite 
coals,  this  single  crucible  may  be  advantageously  replaced  by 

several  of  smaller  size.    When  more  than  one 

One  or  more 

crucibles  is  used,  however,  care  must  be  taken  to  so  reg- 

reqmred.  ulate  the  fire,  that  all  will  be  subjected  to  an 

equal  degree  of  heat  throughout  the  burning. 

174.  The  stone  to  be  tried,  after  being  broken  into  pieces  as 

nearly  equal  in  size  as  possible,  and  not  ex- 
Stone  broken  -,.        T  n        '    \        1      .  . 
into  equal-sized      ceedmg  three-quarters  of  an  mch  cube,  is  m- 

P^®^®^"  troduced  into  the  crucibles,  supposing  several 

to  be  employed,  each  receiving  the  same  number  of  fragments, 

if  practicable.    All  the  crucibles,  with  the  covers  on,  are  then 

imbedded  in  the  fire  and  covered  up  with  coals,  so  that  the  top 

and  bottom  portions  will  attain  a  bright  red 
Smulteneously      ^^^^  simultaneously.    This  last  precaution  is 

essential  to  the  complete  success  of  the  process. 
In  about  forty-five  minutes  after  the  stone  has  reached  a  bright 

red  heat,  one  of  the  crucibles  is  removed  from 

Pieces  removed 

at  equal  intervals  the  fire,  the  others  following  in  succession  at 
of  time.  intervals  of  forty-five  minutes.    In  order  to  se- 

cure similar  results  with  a  single  large  crucible,  two  or  three 
of  the  fragments  are  taken  out  at  the  end  of  the  first  forty-five 
minutes  of  bright  red  heat,  and  others  subsequently,  as  the 
periods  of  time  above  designated  are  reached,  allowing  not 
less  than  four  and  a  half  hours  to  the  last  portions,  or  per- 
haps six  hours,  should  the  stone  be  very  refractory,  which  will 
be  sufficient  to  expel  all  the  carbonic  acid  gas,  and  to  carry 
some  varieties  of  cement  stone,  if  broken  up  as  directed,  to  the 
point  of  incipient  vitrification. 

175.  A  long-continued  bright  red  heat  operates  in  a  singular 
manner  upon  some  argillaceous  varieties  of  cement,  border- 


HYDRAULIC  CEMENTS,  AND  MORTAES.  115 


mg  on  the  intermediate  limes,  in  conferring    j^^^  continued 
apon  them  remarkable  hydraulic  properties  and    heat  sometimes 
energy,  which  they  do  not  possess  at  the  point  of 
complete  calcination,  but  which  may  have  been  present  in  a  lower 
degree  before  all  the  carbonic  acid  was  expelled.    In  order  to 
render  certain  the  detection  of  stone  possessing  this  property, 
when  its  presence  is  suspected,  it  is  recommended  to  continue 
the  calcination  of  some  of  the  fragments  for  eight  or  nine  hours. 

176.  By  means  of  the  several  aforementioned  crucibles,  we 
obtain  portions  of  the  stone  that  are  overburnt,  other  portions 
that  are  insufficiently  burnt,  and  an  intermediate  class,  among 
the  several  members  of  which  will  be  discovered  good  cement, 
if  the  stone  be  capable  of  yielding  it.  There  will  also  be  indi- 
cated, to  an  extent  sufficiently  exact  for  practical  deductions, 
the  relative  degrees  of  calcination  adapted  to  the  several  va- 
rieties operated  upon,  with  their  exact  and  appropriate  maxi- 
mum limits,  respectively.  These  specimens,  unless  the  stone 
belongs  to  some  grade  of  common,  meagre,  or  hydraulic  limes, 
will  not  slake  when  sprinkled  with  water.  Upon  being  sepa- 
rately reduced  to  powder  in  a  mortar,  mixed  to  a  stiff  paste 
with  fresh  water,  and  immersed  in  water  either  fresh  or  salt, 
they  will  indicate  in  their  respective  times  of  setting,  their 
relative  hydraulic  energy,  and  approximately, — though  subject 
to  many  individual  exceptions  in  regard  to  the  ultimate 
strength  of  the  gangs, — their  value  as  cements. 

177.  Whether  the  stone  be  suitable  for  cement,  or  otherwise, 
it  will  be  found,  with  very  few  if  any  exceptions,  that  the 
underburnt  fraerments,  those  which  contain  in    ^  ,  , 

^  '  ^  Underburnt  stone 

the  centre  a  small  core  of  partially  raw  stone,  as  possesses  supe- 
indicated  by  its  density,  color,  and  hardness,  ^^^^^^^^^^J"- 
and  which  effervesce  briskly  with  dilute  hydrochloric  acid,  will 
be  superior  in  hydraulic  activity  to  the  more  highly  calcined 
samples,  and  will  set  under  water  at  65*^  F.,  in  periods  vary- 
ing from  five  to  fifty  minutes.  Those  which  do  not  effervesce 
with  dilute  acid,  and  have  consequently  parted  with  all  their 


116 


PRACTICAL  TREATISE  01^  LIMES, 


carbonic  acid  gas,  will  exhibit  a  less  degree  of  hydraulic  quick- 
ness, and  will  require  a  longer  time  by  twenty-five  to  fifty  per 
Some  overbumt  ^ent.  to  harden  under  water;  while  the  over- 
varieties  nearly  burnt  samples,  those  in  which  the  calcination 
has  proceeded  to  the  verge  of  vitrification,  will, 
in  some  instances,  be  almost  entirely  wanting  in  hydraulic 
activity,  and  in  others,  will  have  this  property  very  much 
impaired.  It  by  no  means  follows  that  this  last-mentioned 
class  is  inferior  to  the  others  in  the  ultimate  energy  and  strength 
The  same  not  gangs  or  mortars ;  on  the  contrary,  some  ce- 

necessarily  of        ments,  the  "  Portland"  for  example,  are  much 

inferior  strength.     .  i  i       i  •     i  pi        .  i 

improved  by  this  degree  oi  burning.  Others, 
however,  are  rendered  entirely  worthless  by  it,  so  that  M.  Pet- 
ot's  assertion  that  "it  is  equally  possible  to  obtain  plastic  (that 
is  hydraulic)  cements  by  a  super-calcination,  and  by  an  incom- 
plete calcination,"  must  be  received  in  a  modified  sense.  Pet- 
Remark  by  M  further  remarks,  that  the  fact  most  worthy  ot 
Petot.  Alleged     notice  is,  that  at  the  point  of  comjplete  calcination 

•'instant  of  i       .n  /  i  i  i  i 

inertia"  of  not  Only  Will  "  the  stone  not  slake,  but  ii  treated 

cements.  ordinary  cement,  will  give  a  substance 

nearly  inert."  ''This  instant  of  inertia  of  plastic  cements,  be- 
tween the  points  of  incomplete  calcination  and  supercalcination, 
seems  to  us  a  capital  fact  in  the  study  of  the  substances.  It  ex- 
plains how  a  suitable  limestone  might  escape  discovery  and  be 
rejected  as  unsuitable,  from  a  simple  fault  of  calcination,  which 
would  not  be  a  fault  with  fat  lime,  or  with  hydraulic  lime." 
Does  not  inva-  poi^^t  of  fact,  there  is  no  such  "  instant 

riably  exist.  qJ^  inertia^''  invariably  existing  between  two 

points  of  maximum  energy,  in  genuine  cements.   It  may  or  may 
not  be  the  case,  according  to  the  composition  and  molecular 
constitution  of  the  stone.     Moreover,  some 

M.  Petot's  deduc- 
tion altogether       cements  have  three  points  of  maximum  energy, 
too  general.  ^^^.^^  ^^^^^^  j^^^^  ^^^^     rj.^^^^  ^^I^.^j^  p^g, 

eess  one,  in  a  pre-eminent  degree,  at  the  point  of  vitrification, 
generally  approximate  to  the  intermediate  limes  in  the  nature 


HTDEAtTLIC  CEMENTS,  AKD  MOKTAES. 


Ill 


and  proportion  of  their  constituent  ingredients.  M.  Petot 
seems  to  have  made  general  a  deduction,  on  evidence  drawn 
from  a  particular  case  only,  and  to  have  simply  opened,  far  less 
exhausted,  the  investigation. 

179.  M.  Yicat's  opinion  that  a  complete  expulsion  of  the 
carbonic  acid  gas,  although  operating  disastrously  upon  the 
intermediate  limes,  is  necessary  in  order  to  fully  develop  the 
merits  of  genuine  cements,  must  also  be  dis- 
carded as  a  rule,  although  individual  cases  in  opSfo?^^^^^*  * 
support  of  it  are  by  no  means  rare. 

180.  If  none  of  the  samples  from  the  crucibles,  except  those 
that  are  considerably  underburnt,  set  under  water,  without 
being  followed  by  cracks,  disintegrations,  or  increase  of  volume, 
the  stone  belongs  to  that  class  termed  intermediate  or  divid- 
ing limes,  already  mentioned,  and  should  be  rejected  with 
scrupulous  care,  unless  provision  can  be  made  Treatment  re 
for  burning  it  by  itself,  and  for  arresting  the  cal-    quired  for  inter- 

mediate  limes. 

cmation  at  the  proper  time. 

181.  By  carefully  subjecting,  from  time  to  time,  the  several 
undivided  layers  of  a  quarry  to  the  trials  above  indicated, 
taking  care  to  secure  a  faithful  fulfilment  of  all  the  conditions 
specified,  so  that  each  will  receive  precisely  the  same  treat- 
ment, we  are  able  to  ascertain  with  sufficient  accuracy,  and  to 
keep  constantly  in  view,  the  peculiar  character  of  each  kind  of 
stone ;  such  as  its  appearance  when  properly  calcined ;  the 
requisite  degree  and  duration  of  heat ;  the  correct  limits  of  cal- 
cination ;  and  consequently  the  best  mode  of  burning  it  on  a 
large  scale  (whether  by  itself  or  mixed  with  the  other  layers), 
and  the  most  advantageous  proportions  in  which  it  should  enter 
into  a  combination  of  the  whole. 

182.  Experience  teaches  us  that  the  physical    Physical  appear- 

ance  of  raw  stone 

appearance  of  calcareous  stones,  which  suni-    no  criterion  of  its 
cieiitly  serves  to  distinguish  and  classify  them,  P^^^P^'^'^i^s- 
when  in  the  natural  state,  into  limestone  and  marbles  of 
various  kinds,  furnishes  no  indication  of  their  qualities  after 


118 


PEACTICAL  TEEATISE  ON  LIMES, 


calcination.  Even  a  chemical  analysis  of  the  raw  stone  is 
to  a  certain  extent  unreliable,  and  deductions  from  it,  under  the 
most  favorable  circumstances,  can  only  be  regarded  as  tolerable 
approximations,  and  are  not  unfrequently  contradictory.  The 
hydraulic  induration  is  due,  in  a  great  measure,  to  the  chemical 
Source  of  combination  of  lime  and  silica,  a  union  which  is 
hydrauiicity.  partially  perfected  in  the  dry  way  during  the  burn- 
ing, and  is  subsequently  carried  on  and  completed  by  the 
agency  of  water.  The  analysis  of  a  cement  stone  after  calcina- 
tion, should  therefore  show  the  commencement  of  this  process 
by  the  presence  of  a  certain  quantity  of  silicate  of  lime. 


QUALITATIYE  EXAMIISTATION  OF  HYDEAULIC 
LIMESTO^^^ES. 

183.  Hydraulic  limestones  are  characterized,  as  a  class,  by 
Mineral  their  fine-grained,  compact,  or  granular  texture, 
characters.  presenting  a  conchoidal  fracture,  yielding  readily 
to  a  file  or  sharp-pointed  instrument,  and  effervescing  more  or 
less  freely,  on  the  application  of  hydrochloric  or  nitric  acids. 

184.  The  prevailing  colors  are  gray,  bluish  gray,  grayish 
white,  and  drab,  with  intermediate  shades. 

185.  The  powdered  mineral  is  more  readily  acted  on  by  the 
acids  than  the  massive  form. 

186.  Hydraulic  limestones  will  generally  be  found  to  con- 
tain silica^  alumina^  oxide  of  iron^  oxide  of  manganese^  limey 
magnesia^  potash^  soda^  with  carbonic^  sulphuric^  and  phos- 
phoric acids^  and  occasionally  some  organic  matter  of  a  bi- 
tuminous nature.  As  some  of  these  may  be  absent,  it  will 
be  necessary  to  ascertain  the  character  of  those  present,  before 
proceeding  to  an  ultimate  qualitative  analysis. 

187.  For  this  purpose,  an  unweighed  portion 
Preparation.  mineral  is  reduced  to  a  fine  powder  in 

an  agate  mortar,  and  digested  in  one  measure  of  water,  for 
eight  or  ten  hours,  aided  by  the  gentle  heat  of  a  sand-bath, 


HYDEAULIC  CEMENTS,  AND  MOETAKS.  119 


and  the  solution  is  then  to  be  filtered  clear,  and  divided  into 
so  many  equal  portions  in  wine  glasses. 

188.  Nitrate  ofharyta  added  to  one  of  these 

*^  .  .  1  .  1    -,  .    T       Sulphuric  acid, 

gives  a  white  precipitate,  which  does  not  dis- 
appear on  the  addition  of  nitric  .or  hydrochloric  acid,  and 
indicates  the  presence  of  suljphuric  acid, 

189.  By  evaporating  another  portion  to  dryness^  in  a  sand- 
bath,  at  a  gentle  heat,  and  igniting  the  residue,  subsequent 
addition   of  hydrochloric   acid,  followed  by 

diluting  with  an  excess  of  water,  will  cause 

the  silica  to  separate  as  a  gelatinous  hydrated  precipitate. 

190.  If  another  portion  be  treated  with  pure  water  of  ammo- 
nia, and  gives  a  pure  white  gelatinous  precipitate,  it  indicates 
the  presence  of  alumina^  or  magnesia^  or  both. 

In  this  case,  hydrochloric  acid  must  be  added,  until  the  pre- 
cipitate is  re-dissolved,  and  the  solution  rendered  distinctly 
acid.    If,  on  the  addition  of  ammonia,  the  pre- 
cipitate reappears  undiminished  in  quantity,  ^^nesL^^^ 
it  contains  alumina  only ;  if  it  be  distinctly 
less  in  quantity,  we  may  infer  rhe  presence  of  both  magnesia 
and  aluinina  ;  but  if  no  precipitate  now  appears,  it  contains 
magnesia  only. 

191.  If  the  precipitate  above  by  ammonia  has  more  or  less 
of  a  brown  color,  the  presence  of  oxide  of  iron  or  ma/ngamjese 
may  be  inferred  ;  but,  if  after  re-dissolving  and 

adding  ammonia  as  above,  the  brown  color  an^tlngaTse. 
disappears,  it  is  due  to  the  oxide  of  mangam^ese 
only.    Should  the  brown  color  still  continue,  it  is  owing 
chiefly  to  the  presence  of  oxide  of  iron. 

192.  If,  after  the  addition  of  ammonia,  the  solution  be 
filtered  to  remove  the  magnesia,  alumina,  the  oxides  of  iron 
and  manganese,  oxalate  of  ammonia  be  added 

to  the  filtrate,  causing  a  white  precipitate,  it 
indicates  the  presence  of  lime, 

193.  K  oxalate  of  ammonia  be  added,  until  all  the  lime  be 


120 


PEACTICAL  TEEATISE  ON  LIMES, 


precipitated,  and  then  filtered,  and  the  filtrate 
Potash  and  soda.  evaporated  to  dryness,  and  ignited  to  destroy 
the  excess  of  oxalate  of  ammonia,  the  residue  if  found  to  be  sol- 
uble in  "Water,  indicates  the  presence  of  potash,  or  soda,  or  both. 

194.  If  upon  treating  the  last  solution  with  pure  bi-chloride 

of  platinum,  no  precipitate  appears,  we  may 
infer  the  presence  of  soda;  but  if  a  yellow 
precipitate  appears,  ^6>toA  is  present  in  the  solution. 

195.  The  yellow  precipitate  of  potash  and  platinum  having 
been  collected  on  a  filter,  the  filtrate  treated  with  sulphide  of 
hydrogen,  and  again  filtered,  to  separate  the  excess  of  bi-chlo- 
ride of  platinum,  and  then  evaporated  to  dryness,  a  residue 
soluble  in  water  remaining,  indicates  the  presence  of  soda. 

196.  Eeturning  to  one  of  the  original  wine  glass  solutions, 
to  which  a  portion  of  strong  nitric  acid  must  be  added,  if  it 

be  then  dropped  into  a  solution  of  molyhdate  of 

Phosphoric  acid.  .  .  . 

ammonia,  and  a  yellow  precipitate  appears,  it 
indicates  the  presence  of  phosphoric  acid. 

197.  The  presence  of  bituminous  matter  is 
matter?^^^  shown  by  the  odor  or  loss  of  weight  upon 

igniting  a  specimen  previously  dried  at  212°F. 

QUAI^TITATIYE  EXAMmATION  OF  HYDKAITLIO 
LIMESTONES. 

198.  It  is  usual,  in  conducting  this  process,  to  ascertain  : 
1st.  The  specific  gravity.    2d.  The  amount  of  hygrometric 

water.    3d.  The  amount  of  phosphoric  acid.    4:th.  The  amount 

of  silica  and  insoluble  matter.     5th.  The  amount  of  alamina- 

6th.  The  amount  of  oxide  of  iron.  7th.  Tlie 
Programme.  .  t     p  o  i  rm 

amount  oi  oxide  oi  manganese.  8th.  1  he  amount 

of  carbonate  of  lime.    9th.  The  amount  of  sulphuric  acid. 

10th.  The  amount  of  potash  and  soda.    11th.  The  amount  of 

carbonate  of  magnesia. 

199.  The  specific  gravity  of  the  specimen  to  be  analyzed 
having  been  determined,  a  portion  of  the  mineral  is  reduced  to 


HYDEAULIC  CEMENTS,  AND  MOETAKS.  121 


mie  powder  in  an  agate  mortar,  and  a  given  quantity,  say  50 
grains,  is  placed  in  a  platinum  crucible  previous- 
ly counterpoised  with  its  cover.    The  crucible  moStuj^^^*^ 
and  its  contents  are  then  to  be  placed  in  a  steam 
bath  oven,  and  heated  for  two  hours,  when  it  is  to  be  cooled  in 
a  receiver  over  sulphuric  acid,  and  then  quickly  weighed.  The 
loss  in  weight  is  the  weight  of  the  uncombined  water. 

200.  The  contents  of  the  crucible  must  then  be  transferred 
to  a  beaker  glass,  and  digested  in  strong  nitric  acid,  to  wliich 
a  little  hydrochloric  acid  has  been  added,  for  forty-eight  hours, 
the   action  being  favored  meantime  by  the 

Phosphoric  acid. 

gentle  heat  oi  a  sand  bath. 

201.  At  the  termination  of  this  process,  the  solution  is  to  be 
filtered,  an  excess  of  molybdate  of  ammonia  added  to  the 
filtrate,  and  the  whole  evaporated  nearly  to  dryness. 

202.  During  the  process,  the  chlorine  of  the  hydrochloric 
acid,  aided  by  the  excess  of  nitric  acid,  decomposes  the  ammo- 
nia of  the  molybdate  of  ammonia,  and  the  molybdic  acid  goes 
down  with  the  phosphoric  acid,  as  jpliospho-molyhdate  of  am- 
monia^ in  the  form  of  a  yellow  precipitate,  with  the  formula : 
2  (3E'H40.P05)  +  15(H0.4Mo03).  Tliis  precipitate  is  insolu- 
ble in  water  and  in  nitric  acid.  After  diluting  the  mixture, 
and  giving  it  time  to  settle,  the  precipitate  is  collected  on  a 
filter,  washed  in  pure  cold  water,  and  while 

T      T      T   .  •/Ill         Phosphoric  acid. 

yet  moist,  dissolved  m  ammonia  (the  beaker 
glass  being  rinsed  with  the  latter,  and  added  thereto). 

203.  From  this  solution  in  ammonia,  sulphate  of  magnesia 
precipitates  all  the  phosphoric  acid  as  ammonia  phosphate  of 
magnesia.  This  is  to  be  washed  with  dilute  water  of  ammonia, 
collected  on  a  filter,  dried,  ignited  at  low  red-heat,  and  weighed, 
— the  filter  having  been  burnt,  and  the  ashes  added  to  the  rest. 

204.  Deducting  the  weight  of  the  filter,  every  100  grains  of 
phosphate  of  magnesia  thus  obtained,  contain  64.06  grains  of 
phosphoric  aoid  j  every  100  grains  of  phosphoric  acid  may 
represent  217.60  of  phosphate  of  lime. 


122 


PKACTIOAL  TREATISE  Olif  LIMES, 


205.  This  determination  of  phosphorio  acid  being  an  inde- 

pendent process,  the  filtered  solution  left  above 
Remark.  .     ,  '       ,        .  , 

IS  thrown  away,  and,  as  in  the  start,  a  new  so- 
lution must  be  prepared. 

206.  Fifty  grains  of  the  same  mineral  prepared  and  dried  as 

before  at  212*^,  are  now  to  be  dissolved  in  strong  hydrochloric 

acid,  the  action  being  favored  by  the  gentle  heat  of  a  sand 

Silica  and  insolu-  bath  for  forty-eight  hours,  after  which,  the  so- 
ble  silicates.  ^^^-^^  ^.^^^^^  ^.^^  ^^^^^^  filtered,— 

and  the  silica  and  insoluble  silicates  washed,  dried,  ignited, 
and  weighed,  are  recorded. 

207.  The  filtered  solution  from  the  preceding  is  then  precip- 
itated by  strong  ammonia,  and  the  precipitate,  consisting  of 

alumina,  oxide  of  iron,  and  phosphates,  after  be- 

Alumina.  .  t/     ^     ^        u.  j. 

ing  well  washed,  is  transferred  while  moist, 
filter  included,  into  a  strong  solution  of  pure  potash,  which  dis- 
solves out  the  alumina. 

208.  This  potash  solution,  filtered  from  the  oxide  of  iron,  &c., 
is  rendered  acid  by  the  addition  of  hydrochloric  acid,  and  the 
alumina  is  then  thrown  down  by  an  excess  of  ammonia,  with 
a  little  sulphide  of  ammonium. 

209.  The  precipitate  thus  obtained  is  washed  with  hot  water, 
dried,  ignited,  and  weighed.  Deducting  the  weight  of  the  fil- 
ter, we  record  the  absolute  weight  of  the  alumina. 

210.  The  oxides  of  iron  and  manganese  remaining  from  the 

potash  solution,  are  dissolved  from  the  filter  in  hydrochloric 

acid,  the  solution  carefully  neutralized  by  am- 
Oxideofiron.  ^    ,  f       .      .         n  > 

moma,  and  then,  upon  the  addition  oi  succi- 
nate of  ammonia,  succinate  of  iron  is  precipitated. 

211.  Upon  filtering  this,  and  adding  ammonia  to  withdraw 
the  succinic  acid,  the  residue  is  washed,  dried,  ignited,  weighed, 
and  the  weight  of  the  oxide  of  iron  ascertained. 

212.  To  the  preceding  filtrate  concentrated  to  a  small  bulk 
by  evaporation,  sulphide  of  ammonium  is  added,  causing  a  pre- 
cipitate of  sulphide  of  manganese.    The  latter,  collected  on  a 


HYDRAULIC  CEMENTS,  Am  MORTARS.  123 


filter,  washed,  dried,  and  thoroughly  roasted^ 
changes  the  sulphide  into  oxide  of  manganese^ 


which  is  then  weighed. 

213.  Return  now  to  the  first  filtrate,  caused  by  the  addi- 
tion of  ammonia  to  the  original  acid  solution,  and  which  con- 
tains the  lime,  magnesia,  and  sulphuric  acid,  ^ 
simultaneously.    With  the  processes  described, 

we  precipitate  the  lime  by  oxalate  of  ammonia.  Collect  it 
after  eight  or  ten  hours  repose,  on  a  filter,  and  weigh  it ;  de- 
ducting the  ashes  of  the  filter,  the  weight  of  carbonate  of  lime 
is  known.    Every  100  grains  contain  44  of  lime. 

214.  The  filtrate  now  contains  a  quantity  of  oxalate  of  am- 
monia, and  ammoniacal  salts,  to  decompose  which  pure  nitric 
acid  is  added  in  excess,  and  the  filtrate  evapo- 

_       .  T     1       1         .  ,      .    -,         Sulphuric  acid. 

rated  to  dryness.  Kedissolve  the  residue  in  hy- 
drochloric acid,  to  which  an  excess  of  nitric  acid  has  been 
added,  and  again  evaporate  to  dryness.  This  dried  residue  of 
nitrates  is  now  drenched  with  pure  acetic  acid,  and  then  wash- 
ed with  water.  Upon  the  addition  of  acetate  of  harytes  to  the 
solution,  the  sulphuric  acid  present  is  precipitated  as  sulphate 
of  harytes^  which  is  collected  on  a  filter,  dried,  and  weighed. 
Every  100  grains  contain  34,31  of  sulphuric  acid. 

215.  The  filtrate  from  the  sulphate  of  barytes  is  now  evap- 
orated to  dryness,  and  transferred  by  a  little  oxalic  acid  and 
water  into  a  small  porcelain  crucible,  in  which  it  is  heated, 
and  again  evaporated  to  dryness,  with  an  excess  of  pure  oxalic 
acid,  which  changes  the  nitrates  into  oxalates. 

216.  The  dried  residuum  thus  obtained  contains  the  alkalies 
and  the  magnesia,  and  must  then  be  perfectly  Alkaline 
ignited,  to  change  all  the  oxalates  into  carbon-  chlorides. 

ates.  In  order  to  separate  the  alkalies  from  the  other  ingredi- 
ents in  this  last  residuum,  it  is  dissolved  and  thoroughly  washed 
through  a  filter  with  water.  The  dissolved  carbonates  contain- 
ed in  the  filtrate  are  changed  into  chlorides  by  the  aid  of  a 
little  hydrochloric  acid,  and  then,  evaporating  the  filtrate  to  dry- 


124 


PKACTICAL  TEEATISE  ON  LIMES, 


ness  and  igniting,  the  saline  residue  is  weighed,  and  the  weigh 
of  the  alkaline  chlorides  of  j[>otassium  and  sodium  recorded. 

217.  Redissolving  the  mixture  of  alkaline  chlorides  in  a 
small  quantity  of  water,  a  solution  of  bi-chloride  of  platinum  is 
added,  and  the  whole  of  the  chloride  of  potassium  present  is 
changed  into  the  double  chloride  of  platinum  and  potassium, 
appearing  as  a  yellow,  insoluble  precipitate. 

218.  Being  evaporated  by  a  gentle  heat  to  near  dryness, 

weak  alcohol  is  added  to  dissolve  the  chloride 

Potash.  T 

01  sodium,  and  any  excess  of  the  platmum  salt 
which  may  be  present.  The  yellow  powder  is  collected  on  a 
filter,  washed  well  with  alcohol,  dried,  and  weighed. 

219.  Every  100  grains  indicate  the  presence  of  19.31  of 
potash,  or  30.51  of  the  chloride  of  potassium. 

220.  The  weight  of  the  chloride  of  potassium  thus  obtained, 

deducted  from  the  weight  of  the  mixed  alkal- 
Soda.  ine  chlorides,  gives  the  weight  of  the  chloride 

of  sodium. 

221.  Every  100  grains  of  the  latter  indicate  the  presence  of 
53.17  of  soda  in  the  limestone. 

222.  The  magnesia  which  remains  in  the  portion  of  the  re- 
siduum which  is  insoluble  in  water,  is  now  dissolved  on  the 

filter  in  diluted  sulphuric  acid,  and  after  evapo- 
Magnesia.  .  ,    .     .  .        .  ,    .  ,  . 

ratmg  and  igniting  m  a  platinum  .  crucible,  is 

weighed  as  sulphate  of  magnesia. 

223.  Every  100  grains  contain  33.33  of  magnesia  ;  100  grains 
of  magnesia  indicate  210  of  carhonate  of  magnesia. 

224.  It  will  be  perceived  by  the  foregoing  process,  that  with 
the  exception  of  the  moisture,  organic  matter,  and  phosphoric 
acid,  which  we  estimated  in  a  separate  quantity  of  the  lime- 
stone, all  the  ingredients  have  been  determined  from  a  single 
weighed  portion,  and  thus  a  check  over  the  whole  is  secured  ; 
for  if  the  sum  of  the  weight,  of  all  the  ingredients  varies  much 
from  the  50  grains  of  limestone  used  at  the  outset,  it  is 
proof  of  errors  in  the  process. 


HYDEAULIC  CEMENTS,  AND  MOETAES. 


125 


225.  Should  the  amount  of  silica  and  insoluble  silicates  be 
Ifrge,  they  should  be  fused  with  three  times  their  weight  of 
carbonate  of  soda,  for  three  or  four  hours,  by  which  they  may 
be  brought  into  a  soluble  condition,  and  the  solution  treated  as 
in  the  foregoing,  and  the  sum  of  the  weights  ascertained. 

TABLE  lY. 

226.  ANALYSES  OF  HYDRAULIC  LIMES,  CEMENTS,  TRASS,  AND  POZZUOLANA. 


2.652 
2.678 
2.680 
2.753 
2.844 
2.735 
2.806 
2.822 
2.793 
2.788 
2.761 
2.786 
2.790 
2.793 
2.781 


Dtash. 

■a 

Ph 

m 

.62 

.40 

12.10 

1.54 

4.64 

31.00 
29.00 
29.77 
31.00 
22.75 


25.20 
19.66 
24.74 
17.84 
18.52 
29.34 
39.74 
19.64 
26.00 
28.08 
18.46 
27, 

11.10 
19.80 


6.16 
3.14 
16.74 
4.60 
2.18 
5.74 
6.00 
7.52 
4.64 
5.72 
4.22 
2.34 
2.52 
4.40 
3.96 


..  14, 
18.20 


34.225 
49.530 


18.00 
17.75 
12.00 
24.00 
9.375 
57.0 
44.5 

23.94 


5, 

6.00 
8.80 
1.31 

17.75 
5.0 

12.0 


40.54 
41.80 
58.25 
43.30 
33.54 
30.74 
30.72 
28.48 
43.32 
37.50 
46.00 
40.00 
33.90 

•ss.eo 

53.3 
65.0 


45.63 
60.00 


17, 

25.152 


30.20 
35.00 
34.08 
30.50 
29.25 
2.6 


11.16 

26.04 

20.80 

14.48 

35.10 

32.86 

14.52 

35.62 

17.76 

39.04 

34.1 

19.26 

22.6 
5.3 


10.38 
17.98 
4.10 


10 


3.875 

9.6 

9.2 


+  1.22 

-  2.68 
+  2.25 
+  1.70 
+  2.04 

—  .72 


—1.60 
—1.40 
+  .44 
+  1.38 
+  .42 
—  .32 


+  .062 
+  .261 


+  ].0t) 
+  .33 
+  5.40 


+  .48 


126 


PRACTICAL  TREATISE  OK  LIMES, 


REFERENCE. 

No.   1,  from  Utica,  La  Salle  county,  Illinois. 


No.   2,  ' 

'      Sandusky,  Ohio. 

No.   3,  ' 

'      Cumberland,  Maryland. 

No.  4,  ' 

'     Shepherdstown,  Yirginia. 

No.   5,  ' 

*     Layer  No.  9 

from  High  Palls,  Ulster 

county,  New  York. 

No.   6,  ' 

*       do.    No.  10, 

11  (( 

(( 

u 

No.   V,  ' 

'       do.    No.  11, 

((  (( 

(( 

(( 

No.   8,  ' 

do.    No.  12 

11  11 

(1 

i( 

No.   9,  ' 

'       do.    No.  13, 

((  (( 

a 

{( 

No.  10,  ' 

'       do.    No.  14, 

U  i( 

(( 

(i 

No.  11,  ' 

'       do.    No.  15, 

U  (( 

(t 

11 

No.  12,  ' 

'       do.    No.  16, 

t(  (( 

(( 

u 

No.  13,  ' 

'       do.    No.  17, 

(I  11 

(( 

It 

No.  14,  ' 

'    Layer  No.  3,  from  Lawrenceville,  Ulster  county.  New  York. 

No.  15,  ' 

'     Akron,  Erie  c 

ounty,  New  York. 

No.  16,  ' 

'     Point-aux-Roches,  Lake  Champlain. 

No.  17,  ' 

'     Layer  No.  11,  from  Round  Top  Cement  "Works,  near  Hancock,  Md 

No.  18.  Yassy  (France)  cement. 

No.  19.  Theil  (France)  limestone  (raw). 

No.  20.  Theil  hydraulic  lime,  from  the  above. 

No.  21,  from  Balcony  Falls,  Rockbridge  county,  Virginia  (raw). 

No.  22,    "  do.  do.         do.        do.  (burnt). 

No.  23.  Calderwood  (Scotland)  Roman  cement  (raw). 

No.  24.  Sheppy  (England)  No.  1  cement  stone. 

No.  25.     do.  do.      No.  2  do. 

No.  26.  Southend  (England)  cement  stone. 

No.  27.  Yorkshire      do.  do. 

No.  28.  Harwich       do.  do. 

No.'  30:  Pozzuolana,  [  "'"^  ^reussart,  at  Strasburg. 

No.  31,  from  Lockport,  Niagara  county.  New  York  (burnt,  rather  old). 

227.  The  samples  from  Nos.  1  to  15,  inclusive,  were  analyzed 
by  Professor  E.  C.  Boynton,  Oxford  University,  Mississippi ; 
Nos.  16  and  17  by  Lieutenant  Caleb  Huse,  Asst.  Inst.  Chem., 
etc.,  U.  S.  Mil.  Academy;  ISTo.  23  by  Professor  F.  Penny, 
Ph.  D.,  F.  C.  S. ;  ISTos.  29  and  30  by  Berthier;  the  others  were 
derived  from  reliable  sources. 

228.  All  the  manufacturers  of  cement  in  the  United  States, 
pursue  essentially  the  same  process,  in  preparing  the  article  for 
market.  The  only  difference  worthy  of  notice  is,  that  while 
some  use  for  burning  the  stone  the  ordinary  perpetual  kiln,  of 


HYDEAULIC  CEMENTS^  AND  MORTAES.  127 


a  cylindrical  form  very  nearly,  terminating  at  the  bottom  in  the 
inverted  frustum  of  a  right  cone,  in  which  the  raw  stone, 
broken  into  pieces  of  random  size,  but  measur- 

.  .  Kilns  used  for 

ing  not  more  than  8  in  the  longest  dimen-  burning  cement 
sions,  and  the  fuel  (either  bituminous  or  an- 
thracite  coal)  are  mixed  together  in  alternate  layers,  extending 
to  the  top  of  the  kiln ;  others  prefer  the  perpetual  "  furnace 
kiln,"  in  which  the  heat  is  applied  by  means  of  furnaces,  suit- 
ably arranged  for  wood  or  coal,  near  the  bottom  of  the  kiln, 
In  some  localities,  as  at  Utica,  Illinois,  intermittent  kilns, 
burning  bituminous  coal,  are  used. 

229.  For  kilns  of  the  first  above-mentioned  class,  when  an- 
thracite coal  is  used,  the  latter  should  be  broken  up  very  fine. 
What  is  technically  known  as  "  second  screenings,"  or  "  pea 
and  dust,"  at  the  mines  of  the  Delaware  and  Hudson  Canal 
Company,  and  the  Pennsylvania  Coal  Company,  has  been 
found  to  give  the  most  satisfactory  results  in  Ulster  county, 
"New  York,  among  the  Kosendale  Works,  and  can  be  obtained  at 
a  trifling  advance  on  the  cost  of  transportation  from  the  mines. 

230.  Whether  anthracite  or  hituminous  coal  be  used  for 
burning,  the  quantity  requisite  and  proper  to  be  used  will  de- 
pend not  only  upon  its  kind  and  quality,  but  upon  the  charac- 
ter and  composition  of  the  cement  stone,  the  form  and  locality 
of  the  kiln,  and  the  skill  of  the  burner.  In  the  works  situated  on 
the  Potomac  Piver,  at  Shepherdstown,  Hancock, 

and  Cumberland  respectively,  the  Cumberland  ^""^^ 

semi-bituminous  coal  is  used  for  burning ;  and, 

according  to  the  opinion  of  Chas.  H.  Locher,  Esq.,  proprietor 

of  the  James  Piver  Cement  Works,  at  Balcony  Falls,  Virginia, 

is  superior  to  the  bituminous  coal  used  by  him, 

obtained  near  Pichmond,  Virginia.    3,500  lbs.  ^""^^ 

*— '  '  necessarj'. 

of  anthracite  coal  is  sufficient  to  burn  100  bar- 
rels of  cement,  of  300  lbs.  each. 

231.  The  ordinary  perpetual  kiln  is  set  in  operation  by  first 
filling  it  with  thin,  alternate  layers  of  coal  and  raw  stone,  and 


128 


PRACTICAL  TREATISE  ON  LIMES, 


Starting  the  kiln. 


then  igniting  it  from  below  with  light,  dry  wood. 
The  layers  of  stone  should  not  exceed  six  inches 
in  thickness.  The  burnt  stone  is  drawn  out  at  the  bottom,  twice 
or  thrice  every  twenty-four  hours,  raw  stone  and  coal  being 


Fig.  11. 


added  in  suitable  proportions  at  the  top  after  each  drawling. 

Fig.  11  represents  a  vertical  section,  through  the 
uaf  kifns.  ^^^^  draw-pit,  of  the  kilns  used 

in  Maryland  and  Yirginia  ;  and  Fig.  12,  of  those 
preferred  in  New  York  and  Ohio. 

232.  There  are  serious  defects  in  the  method  of  burning 
above  indicated,  for  which  no  easy  and  practi- 
of^burning!^^*^^*^    cable  remedy  has  yet  been  devised,  unless  it  be 
the  furnace  kiln  or  some  modification  of  it. 
Some  of  the  stone  becomes  so  much  overburnt,  having  reached 
the  stage  of  incipient  vitrification,  as  to  be  not  only  very  vari- 
able in  quality  among  the  products  of  the  sev- 
unSrburntTtone.    ^^^^  ^^jers,  and  in  many  cases  quite  worthless, 
but  exceedingly  hard  and  tough,  and  conse- 
quently difficult  to  reduce  to  powder ;  while  another  portion, 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


129 


usually  the  largest  fragments,  or  those  that  have  subsided  too 

rapidly  in  the  drawing,  are  underburnt  and  perhaps  partially 

raw  inside.*    These  also,  being  difficult  to  grind,  should  be 

selected  out  and  subjected  to  a  second  calcination.  Much  of  it, 

however,  finds  its  way  into  the  cement,  and  as    superior  activity 

the  subcarbonates  are  known  to  be  very  prompt  subcarbo- 

nates. 

in  hydraulic  energy  during  the  incipient  indu- 
ration, the  injurious  effect  of  the  adulteration  is  not  detected 
by  ordinary  tests. 

233.  Lying  between  the  two  varieties  of  burnt  stone  just 
mentioned,  one  of  which  quite  generally,  and 
the  other  quite  frequently,  produces  cement  p^od^c^s^^^^^ 
greatly  inferior  in  quality  to  that  which  the 
stone,  properly  treated,  is  capable  of  yielding,  we  find  another 
considerable  portion,  either  too  much  or  not  enough  burnt  to 
develop  the  maximum  energy  and  value  of  the  cement,  or  in 
the  general  case,  a  mixture  of  both  of  these  extremes,  which 
offers  no  distinguishing  physical  feature  by  which  it  is  possible 
to  assort  it  from  the  rest.    With  some  varieties  of  stone,  these 
inferior  products   are  yielded,  by  a  heat  of 
moderate  intensity  and  duration,  at  a  stage  but    SLtion  varies 
little  in  advance  of  a  condition  of  incomplete    '^^^^  different 

stones. 

calcination ;  with  others^  they  are  produced  as 
we  approximate  to  a  state  of  incipient  vitrification;  with  aU^ 
they  are  essential  elements  in  the  individual  properties  of  the 
stone,  each  quarry,  and  even  the  separate  layers  of  the  same 
quarry,  possessing  distinct  characteristic  features  in  this  re- 
spect, which  features  are,  withal,  subject  to  considerable  vari- 
ations within  very  narrow  lateral  limits.  The  converse  of  these 
premises  is  also  true,  to  wit,  that  the  state  of  maximum  energy 
corresponds  to  a  condition  of  incomplete  calcination  in  some 
cases  ;  of  complete  calcination  in  others ;  while  in  others  still, 
it  is  only  produced  by  vitrification  more  or  less  complete.  We 

*  It  wiU  be  seen  hereafter,  that  some  varieties  of  stone  require  to  be  overburnt  to 
the  stage  of  incipient  vitrification,  to  develop  their  full  value  as  cements. 

9 


130 


PEACTICAL  TEEATISE  ON  LIMES, 


therefore  see  the  necessity  for  resorting  to  what 
SamfnatioTor*  appears  to  be  the  only  efficient  method  of  elim- 
stones  neces-       inatinff  these  elements  of  inferiority  in  hydran- 

sary.  ^  '  .  . 

lie  cement,  viz :  a  constant  daily  examination 
of  the  stone  by  adequate  tests,  combined  with  a  calcination  in 
separate  kilns  of  all  those  layers  in  a  quarry  which  possess 
marked  features  of  dissimilarity. 

234.  Suitably  burnt  cement  may  therefore  contain  a  nota- 
ble quantity  of  carbonic  acid  gas,  and  effervesce  briskly  with 

Each  variety  dilute  hydrochloric  acid,  or  it  may  not,  accord- 

requires  special      ing  to  inherent  properties  in  the  article  itself. 

Each  variety  requires  a  special  mode  of  treat- 
ment, as  to  the  duration  and  intensity  of  the  heat  to  which  it 
should  be  subjected.  This  great  difference  is,  perhaps,  mainly 
due  to  the  variable  amounts  of  silica  and  the  alkalies  which 
the  stone  contains,  but  is  by  no  means  entire - 
Sof!^  ly  dependent  on  them.    Other  ingredients  ex- 

ercise an  important  influence,  particularly  those 
which  act  as  fluxes.  The  obscure  reactions  which  take  place 
at  high  temperatures,  when  a  compound  limestone  is  under 
treatment,  cannot  be  accounted  for  by  any  general  theory. 
It  is  fortunate  that  we  are  able,  in  a  measure,  to  comprehend 
and  estimate  the  results. 

235.  The  great  abuse  to  be  abolished,  is  the  mingling  of  dis- 
similar stones  in  burning.  When  this  is  done,  most  if  not  all 
Dissimilar  stones  Elinor  evils  will  disappear.  The  idea  that  sev- 
shouldnotbe       eral  kinds  of  cement  stone^ — some  of  which 

burned  together.  .  i  •  i  r> 

require  twenty,  some  thirty,  and  some  forty 
hours,  calcination — can  be  burnt  together,  in  the  same  kiln,  is 
both  theoretically  and  practically  absurd.  Very  little  extra 
expense  would  be  involved  in  a  suitable  separation  and  classifi- 
cation of  the  stone  during  the  process  of  quarrying,  and  few  of 
the  manufacturers  would  require  any  more  kilns  than  they 
usually  keep  going.  The  least  extensive  works  keep  from 
three  to  five  in  operation,  with  one  or  two  in  reserve,  and  there 


HTDEAULIC  CEMENTS,  AND  MOETARS.  131 


are  few  quarries  that  would  require  a  more  extensive  subdi- 
vision than  these  would  accommodate. 

236.  Besides  the  several  inferior  products  of  the  kiln  just 
noticed,  which  are  due  to  differences  in  the  properties  of  the 
stone,  there  are  others  of  a  similar  character,  which  have  their 
origin  in  causes  to  a  certain  extent  independent  of  these 
properties,  and  which,  with  proper  precautions,  are  more  or  less 
under  control :  such  as  variations  in  the  force  of  the  draught 
through  the  kiln,  due  to  changes  either  in  the  direction  and 

force  of  the  wind,  or  in  the  barometric  state  of    ^  ^  . 

'  Certain  causes 

the  atmosphere  ;  neglecting  to  draw  the  burnt    of  bad  burning 

.  ,      ,  .  .  -  .  ,  within  control. 

stone  with  the  requisite  care,  taking  perhaps 
equal  quantities  at  stated  times,  which  may  be  either  too  much 
or  not  enough,  depending  on  circumstances ;  not  preserving 
the  proper  proportion  between  the  fuel  and  raw  stone,  when 
adding  these  at  the  top,  or  not  adding  them  at  the  proper  time 
and  in  the  suitable  quantities ;  irregularities  in  the  settling  of 
the  stone  in  the  kiln  at  each  drawing,  which  result  in  some 
portions  being  exposed  to  the  heat  a  much  longer  time  than 
others ;  the  formation  of  "  cinders,"  or  vitrified  pieces  of  stone, 
which  adhere  together  or  to  the  sides  of  the  kiln,  choking  the 
draught,  and  retarding  the  expulsion  of  the  carbonic  acid  gas : 
these,  and  many  other  variable  causes,  will  always  operate  to 
such  an  extent  as  to  render  the  proper  calcination  of  the 
cement  an  operation  of  the  utmost  delicacy,  and  one  requiring 
on  the  part  of  the  manufacturer,  a  high  order  of  intelligence, 
experience,  and  skill.  Even  supposing  that  all  the  stone  yielded 
by  a  quarry  and  introduced  into  the  cement  is  alike  in  compo- 
sition and  character,  and  requires  the  same  treatment  in  burn- 
ing, the  theory  upon  which  this  practice  of  mixing  the  fuel  and 
stone  together  in  the  kiln  avowedly  rests,  is  singularly  at  fault, 
and  will  by  no  means  bear  a  critical  examination ;  for, 
inasmuch  as  all  the  coal  is  consumed,  or  sup-    Theory  of  mixing 

posed  to  be  consumed,  during  the  calcination,—    the  stone  and  fuel 
,        .  .      ,  ,  ,     not  tenable. 

otherwise  it  is  drawn  m  the  cement  and  ground 


132 


PEACTICAL  TREATISE  ON  LIMES, 


up  in  it ; — and  as  the  proportion  between  the  amount  of  fuel 
and  raw  stone,  as  well  as  the  times  of  drawing  the  kilns  and 
the  quantities  drawn  are  also  pre-established ;  and  as  no  provi- 
sion is  made  to  regulate  the  force  of  the  draught,  with  a  view 
to  anticipate  in  a  measure  the  intervention  of  one  of  the 
principal  causes  of  variation  referred  to,  it  virtually  assumes 
that  a  moderate  heat,  long  continued,  and  a  high  heat,  pro- 
portionally short  in  duration,  will  produce  identical  results, 
a  premise  which,  with  all  its  apparent  plausibility,  is  directly 
opposed  to  the  teachings  of  experience. 

237.  A  perpetual  "flame"  or  "furnace"  kiln,  for  burning 
either  lime  or  cement,  patented  by  Mr.  C.  D.  Page,  of  Roches- 
ter, Y.,  has  recently  been  extensively  introduced  into  the 
western  part  of  the  State  of  New  York,  which  is  intended  to 
obviate  some  of  the  most  glaring  defects  of  all  that  class  of 
kilns  which  require  the  fuel  and  stone  to  be  mixed  together. 
Either  wood  or  coal  may  be  used  for  fuel,  although  the  details 
of  the  arrangements  for  supplying  the  heat  are  not  exactly  the 
same  in  each  case.  Figs.  13  to  18  represent  sections  of  these 
kilns,  whose  horizontal  section  of  the  interior  of  the  cupola  is, 
it  will  be  observed,  of  an  oval  or  elongated  form,  with  grates  and 
flues  ranged  along  either  side.  The  conjugate  axis  of  this  oval, 
on  a  level  with  the  fire,  should  not  exceed  five  feet  six  inches. 
Its  traverse  axis  may  be  increased  to  any  length  necessary  to 
attain  a  given  capacity,  the  coal-grates  being  correspondingly 
prolonged  ;  and  when  the  enlargement  is  considerable,  suitable 
openings  for  drawing  the  burnt  stone  being  made  at  the  proper 
intervals  along  the  sides.  A  little  above  the  point  where  the 
flame  plays  directly  upon  the  stone,  small  horizontal  openings, 
Q,  called  "  peak  holes,"  are  provided,  which  extend  through 
the  walls  of  the  kiln  into  the  cupola,  and  through  which  the 
progress  of  the  burning  may  be  ascertained  from  time  to  time, 
with  a  view  to  regulate  the  times  of  drawing  the  burnt  stone, 
and  the  amount  to  be  drawn.  At  the  bottom  of  the  kiln,  and 
dividing  the  lower  part  of  the  cupola  into  two  symmetrica] 


HYDEAULIC  CEMENTS,  AND  MOETARS. 


133 


parts,  a  vertical  division  wall,  O  (Figs.  14, 15,  and  16),  is  placed, 
which  extends  a  little  above  the  level  of  the  furnaces,  the 
object  of  which  is  to  prevent  a  horizontal  draught  through  the 
kiln.  In  burning  common  lime,  this  is  sometimes  omitted, 
or  replaced  by  a  wedge-shaped  "  air-saddle,"  through  which 
a  current  of  cold  air  constantly  passes,  which  divides  and 
gradually  cools  the  lime  as  it  falls  below  the  fires,  thereby 
rendering  it  less  liable  to  injury  from  spontaneous  slak- 
ing. 

238.  All  who  have  used  this  kiln,  whether  for  lime  or  ce- 
ment, so  far  as  any  statements  have  been  received  from  them, 
consider  its  success  perfect,  and  dpu-tk  of  it  in  the  highest 
terms.  Mr.  Lemuel  Thompson,  or  Koclieste.i  N"  Y.,  who  used 
one  of  them  for  burning  lime,  says:  '^^  My  kilr  is  but  28  feet 
in  height,  yet  I  have  been  able  to  burn  320  bnshels  of  perfect 
lime  with  3|-  cords  of  wood  m  twenty-foiii  hours,  and  that, 
while  the  kiln  was  new.  and  of  course,  somewhat  damj .  The 
fires  are  applied  at  four  points,  producing  a  uniform  heat  on 
all  points  of  the  stone,  and  leaving  not  a  stone  unburnt.  I 
find  that  I  have  burnt  44,000  bushels  of  perfect  lime,  w^ith  394 
cords  of  wood,  being  114  feet  or  wood  to  100  bushels  of  lime 
on  the  average  ,  during  which  time  I  let  the  fire  go  down  many 
times,  owing  to  want  of  market  for  the  lime,  and  by  so  doing, 
losing  a  large  amount  ol  heat.  1  never  drew  the  kiln  down 
the  entire  period  of  my  running  it ' 

239  One  of  them  is  in  use  for  burning  cement  at  Akron,  Erie 
county  IN  Y,.,  by  Messrs.  Newman  &  Bro.  Under  date  of 
March  12th,  1859,  these  gentlemen  say  :  "  We  are  now  burning 
^>ur  100  barrels,  on  account  of  the  dulness  of  the  market, — 
we  can  burn  130  barrels  every  twenty-four  hours  with  three 
Gords  of  wood.  The  peculiar  shape  of  the  cupola  and  furnaces 
are  such,  that  the  cement  is  perfectly  and  uniformly  burnt, 
which  adds  20  per  cent,  to  the  value  of  our  cement  over  that 
obtained  by  the  old  mode  of  burning.  Now,  we  know  just 
what  we  can  depend  upon  every  day ;  we  get  no  raw  stone,  no 


134 


PRACTICAL  TREATISE  ON  LIMES, 


cinders,  nothing  but  pure  cement.  We  can  grind  one-fourth 
nioi'e  of  this  cement  and  with  less  power." 


-A. 


Eig.  13.  Fig.  14. 


Fig.  13  shows  a  front  elevation  of  the  kiln  witli  ten  furnaces, 
designed  for  anthracite  coal,  although  bituminous  coal  may 
be  used  in  it,  without  any  change  being  required.  A  sec- 
tion of  the  same,  through  A  B,  is  represented  in  Fig.  14,  and 
through  C  D,  in  Fig.  15.  When  wood  is  used  for  burning,  the 
kiln  is  constructed,  as  represented  in  Fig.  16,  with  four'  fur- 
naces, and  in  Figs.  17  and  18  with  two  furnaces.  The  parts 
marked  K,  show  the  crib  at  the  top  of  the  cupola  ;  L  and  M, 
are  timbers  intended  to  bind  the  walls  together ;  Q,  are  the 
peak  holes,  through  which  the  progress  of  the  burning  can  be 
watched ;  R,  the  feed  ovens,  for  heating  the  coal,  before  it 


HYDEAULIC  CEMENTS,  AND  MOETAES, 


135 


passes  throiio'li  the  dampers,  S,  into  the  furnaces,  T ;  U,  the 
ash-pits ;  Y,  the  draw-pit ;  and  W,  a  platform  in  front  of  the 
furnaces. 


Fig.  17. 


240.  In  order  to  have  the  advantages  claimed  for  this  kiln 
f ul  I y  tested,  under  circumstances  that  would  lead  to  conclusive 
results,  it  was  suggested  to  the  Newark  &  Rosendale  Company 


136 


PEACTICAIi  TEEATISE  ON  LIMES, 


to  give  it  a  thoroiigli  trial  at  their  works  in  Ulster  county,  to 
which  they  readily  consented.  They  adopted  the  coal-burning 
pattern  (Figures  13,  14,  and  15),  which  was  erected  during 
the  autumn  of  1859,  under  the  personal  supervision  of  the 
patentee. 

241.  The  value  of  the  flame  Tcihi^  as  compai-ed  with  the  draw 
kiln,  in  which  the  stone  and  fuel  are  mixed  together  in  alter- 
nate layers,  may  be  inferred  from  the  results  given  in  Table  Y. 
The  cements  used  for  the  mixtures  recorded  in  this  table,  were 
produced  by  combining,  in  equal  proportions,  the  upper  and 
the  lower  series  of  cement  layers  as  developed  in  the  quarries 
of  the  I^ewark  &  Rosendale  Company,  at  Whiteport,  Ulster 
county.  New  York.  This  is  the  same  combination  which  that 
company  makes  use  of  in  manufacturing  for  the  market.  In 
Table  Y.,  the  two  cements  under  trial  are  designated  Flame 
Kiln  cement  and  Dram  Kiln  cement.  They  were  samples  of 
two  lots  made  on  the  same  day ;  one  having  been  burnt  in 
the  new  and  the  other  in  the  old  form  of  kiln. 

242.  TABLE  Y. 

Shows  the  ultimate  strength  of  rectangular  parallelopipeds  of 
mortar  (2"  x  ^"  X  8"),  from  cement  calcined  in  different  kilns, 
formed  in  vertical  moulds,  under  a  pressure  of  thirty-two  pounds 
per  square  inch  applied  at  the  upper  end  until  the  mortar  had 
"  set,"  and  broken  on  supports  four  inches  apart  by  pressure 
from  above,  midway  between  the  points  of  support.  The  mor- 
tars were  kept  in  a  damp  place  for  twenty-four  hours,  and  then 
immersed  in  salt  water.   Age  of  mortars,  ninety-five  days. 

243.  Ohservations  on  the  following  Table. — The  Draw  Kiln 
cement  of  the  following  table  was  not  quite  so  quick-setting  as 
the  Newark  &  Rosendale  cement  usually  is.  It  is  possible 
that  the  mortars  made  from  it  are  correspondingly  inferior  in 
strength  and  tenacity ;  although  such  a  result  would  not,  by 
any  means,  necessarily  follow.  Neither  of  the  cements  in 
Table  Y.  comes  up  to  the  standard  quality  of  the  best  Eosea* 


HYDRAULIC  CEMENTS,  AND  M0RTAE8.  137 


TABLE  Y. 


Composition  of  the  mortar. 


^3 


Mame  kiln. 


Draw  kiln. 


Flame  kiln. 


Draw  kiln. 


Pure  cement  (stiff  paste.). 


Dry  cement  vol.  1,  Sand  vol.  2,  (stifi'  mortar.) 


499^  lbs. 


360f 


462' 
510 
447 
529 
541  I' 
573 
470 
462 
400' 
400 
322 
314 
391 
369 
337 
353 
369^ 
373 
267 
259 
297 
307 
314 
353 
341 
279 
291 
220' 
291 
291 
248 
244 

197  y22S-i\  lbs. 
197 
202 
204 
209 
213  J 


313ff  Rtf: 


dale  brands.  They  both  range  low  in  their  breaking  weights. 
As  they  were  derived  from  one  day's  yield  of  quarry,  and  were 
manipulated  and  broken  consecutively  under  the  same  condi- 
tions, the  inference  is,  that  sudden  variations  in  the  quality  of 
the  stone  enter  largely  into  the  causes  of  this  inferiority.  In 


138 


PEACTICAL  TREATISE  ON  LIMES, 


fact,  it  is  upon  this  hypothesis  only  that  many  striking  dis- 
crepancies in  the  resistance  of  cements  from  the  same  quarry, 
treated  precisely  alike,  and  brought  into  market  during  the  same 
month,  can  be  explained.  This  illustrates  the  necessity  of  the 
precaution  adopted  and  adhered  to  in  all  the  trials  reported  in 
this  work,  of  never  assuming  identity  in  quality  of  separate  sam- 
ples from  the  same  manufactory,  or  even  from  different  barrels 
of  the  same  cargo,  and  of  preserving  within  the  range  of  each 
series  of  experiments,  the  means  of  an  independent  comparison 
of  results. 

The  cement  used  for  Table  Y.,  paragraph  242,  and  Table 
XXYIL,  paragraph  547,  for  example,  came  from  the  same 
quarry,  were  identical  in  the  proportion  adopted  for  combining 
the  several  strata,  and  were  treated  in  precisely  the  same  man- 
ner ;  yet  in  one  the  breaking  weight  of  the  cement  paste,  without 
sand,  is  only  499|-  pounds  for  the  flame  kiln  product,  and  360| 
pounds  for  that  of  the  draw  kiln  ;  while  in  the  other  (burnt  in 
the  draw  kiln),  it  reaches  as  high  as  1,002  pounds,  and  it  is  only 
when  about  133  per  cent,  of  lime  paste  is  added,  that  the  inferior 
limit  of  360f  pounds  is  approximately  reached.  This  affords 
another  proof  of  the  necessity  of  keeping  a  close  and  constant 
watch  upon  the  quarries  and  kilns,  and  of  pursuing  a  rigid  sys- 
tem of  daily  tests,  to  guard  against  deterioration  in  quality. 

244.  Perpetual  kilns  are  always  to  be  preferred  to  those  that 
are  intermittent^  for  burning  either  lime  or  cement,  on  account 
of  the  smaller  quantity  of  fuel  which  they  consume.  As  the 
object  is  chiefly  to  expel  the  water  and  carbonic  acid,  for  which 
a  bright  red  heat  is  sufficient,  the  most  crude  devices  are  some- 
times resorted  to,  in  order  to  accomplish  this  result.  For 
making  common  lime,  a  rude  pile  of  logs,  burning  in  the  open 
air,  with  the  limestone  thrown  on  the  top,  has  frequently  been 
made  to  answer.  Cement,  in  case  of  necessity,  might  also  be 
calcined  in  the  same  manner.  As  its  manufacture,  however, 
is  seldom  resorted  to,  except  to  supply  a  somewhat  extensive 
demand  of  trade,  and  as  its  calcination  requires  considerable 


HTDEAULIC  CEMENTS,  AND  MOETAES.  139 


ekill,  to  produce  an  article  of  even  medium  quality,  this  primi 
tive  mode  is  seldom  resorted  to.  Of  all  known  methods  of 
burning,  it  is  tlie  most  expensive  in  the  consumption  of  fuel. 

245.  For  burning  common  lime,  the  simplest  form  of  kiln  in 
common  use  in  Europe  (and  with  some  slight  modifications,  in 
the  United  States),  is  that  represented  in  Fig.  19,  in  which  wood 


Fig.  19. 


is  used  for  fuel.  This  kiln  is  circular  in  horizontal  section,  and 
is  generally  constructed  of  rough-hammered  limestone  without 
mortar.  It  is  usually  located  on  the  side  of  a  hill,  so  that  the 
top  is  accessible  for  charging  the  kiln,  and  the  bottom  for  sup- 
plying the  fuel,  and  drawing  the  burnt  lime.  The  largest 
pieces  of  the  stone  to  be  burnt  are  first  selected  and  formed 
into  an  arch,  c,  c.  Above  this  arch,  the  kiln  is  filled  by 
throwing  the  stone  in  loosely  from  the  top,  taking  the  largest 
first,  and  the  smaller  pieces  afterwards.  These  latter  are  also 
piled  up  above  the  mouth  of  the  kiln.  The  arched  entrance, 
C,  afibrds  a  convenience  for  supplying  the  fuel. 

246.  A  necessary  precaution  in  using  intermittent  kilns  of 


140 


PEACTICAL  TREATISE  ON  LIMES, 


this  class  is,  that  the  heat  should  be  raised  gradually  to  the  re- 
quired degree.  There  is  a  controlling  reason  for  this  :  a  sud- 
den elevation  of  temperature  will  cause  a  sudden  expansion  of 
the  stones,  c,  c,  c,  and  the  moisture  will  be  driven  off  with  such 
force  as  to  rupture  them  in  many  cases.  As  these  stones  are  of 
irregular  shape  and  unconnected  with  mortar  of  any  kind,  the 
consequence  might  be  a  downfall  of  the  entire  contents  of  the 
kiln,  and  of  course  an  interruption  of  the  burning.  Moreover, 
a  too  sudden  elevation  of  temperature  might  cause  many  of 
the  stones  to  break  up  into  small  pieces,  and  thereby  seriously 
choke  the  draught,  without  injuring  the  arch. 

247.  In  all  intermittent  kilns,  there  is  an  enormous  waste  of 
fuel,  as  tlie  furnace  must  cool  each  time  it  is  discharged^  and 
the  quantity  of  fuel  expended  in  raising  the  contents  of  the 
kiln,  as  well  as  its  thick  side-walls,  to  the  point  necessary  to 
burn  lime,  has  to  be  repeated  each  time  the  kiln  is  recharged. 

There  are  other  defects :  the  stone  nearest  the  fire  is  liable  to 
become  injured  by  overburning,  before  the  top  portions  become 
fully  caustic. 

248.  A  better  form  of  intermit- 
tent kiln  is  shown  in  Fig.  20.  Be- 
sides the  outer  wall  of  stone  mason- 
ry, there  is  an  interior  one  of  fire- 
bricks. The  fireplace,  J,  rests  on 
a  permeated  brick  arch,  through 
which  there  is  a  sufficiently  free  cir- 
culation of  air,  to  secure  the  neces- 
sary draught. 

249.  Perjpetual  or  draw  kilns  are 
intended  to  obviate  the  evils  of  irreg- 
ular calcination,  and  useless  expense  of  fuel,  attendant  on  inter- 
mittent kilns.  A  very  simple  form  of  perpetual  kiln,  for  burn- 
ing lime  with  coal  interstratified  with  the  stone,  is  represented 
in  Figs.  21,  22,  and  28.  It  is  much  used  on  the  continent  of 
Europe.    The  interior  is  an  inverted  frustum  of  a  cone,  from 


HYDEAULIC  CEMENTS    AND  MORTAKS, 


141 


-/p/-  -> 

— 


Fig.  21. 

five,  to  five  and  a  half  feet  in  diameter  at  the  bottom,  and  from 
]iine  to  ten  feet  at  top,  and 
thirteen  to  fourteen  feet 
high.  It  may  be  hirger. 
This  is  generally  surround- 
ed by  a  thick,  circular  wall, 
from  twenty  to  twenty-one  ^'^S-  22. 
feet  in  diameter,  pierced  at  the  bottom  Fig.  23. 

with  three  apertures  for  drawing  the  burnt  lime. 

The  draught  may  be  regulated  by  doors  placed  at  the  en- 
trance to  the  apertures. 

A  kiln  of  this  form  and  of  the  dimensions  indicated  above, 
ought  to  yield  about  500  cubic  feet  of  quicklime  every  twenty- 
four  hours,  with  a  consumption  of  about  two  tons  of  coal.  The 
quantity  of  coal,  however,  varies  considerably  with  its  kind  and 
quality,  and  with  the  character  of  the  stone  to  be  burnt ;  some 
reaching  as  high  as  one-fourth  of  the  weight  of  the  limestone. 

250.  In  all  kilns  of  this  description,  when  the  stone  and  coal 
are  mixed  together,  the  burning  is  started  by  first  placing  a 
layer  of  light- wood  at  the  bottom  of  the  kiln,  then  a  layer  of 
coal  on  the  wood,  and  then  a  layer  of  limestone.  Layers  of 
coal  and  limestone  follow  alternately,  until  the  kiln  is  filled, 
and  the  stone  is  piled  upon  the  top  of  the  kiln.  When  the 
lime  near  the  bottom  is  sufficiently  burnt,  the  drawing  of  it 


142 


PRACTICAL  TREATISE  01^  LIMES, 


commences,  and  may  follow  constantly  at  intervals  of  lialf  an 
bonr.  In  some  localities,  it  is  customary  to  draw  but  three  or 
four  times  every  twenty-four  hours. 

251.  In  the  consumption  of  coal,  a  small  quantity  of  ash  is 
produced,  which  is  easily  separated  from  the  burnt  lime. 
Wood  is  not  so  easily  distributed  as  coal,  uniformly  through  the 
kiln,  on  account  of  the  difficulty  with  which  it  is  reduced  into 
small  pieces  ;  and  even  if  it  could  be  thus  distributed,  the  large 
quantity  of  ash  which  it  produces,  taken  in  connection  with  a 
more  or  less  considerable  quantity  of  small  fragments  of  stone, 
caused  by  the  disintegrating  influence  of  heat,  would  have  a  ten- 
dency to  interfere  seriously  with  the  draught  of  air  through  the 
kiln.  As  before  remarked  (paragraph  237),  Page's  kilns  are 
used  for  burning  both  cement  and  lime,  in  the  western  part  of 
the  State  of  'New  York.  These  kilns  were  introduced  into 
Maine  four  or  five  years  since,  for  burning  Thomaston  or  Rock- 
land lime.    They  have  received  various  modifications  in  form 


i 


Fig.  24.     '  Fig.  25. 

md  detail  since  that  time.  Figures  24,  25,  26,  and  27  repre- 
sent a  stack  of  two  of  the  kilns  now  in  general  use  in  Eockland. 

252.  When  lime-burning  is  conducted  on  a  small  scale  in 
one  kiln,  two  furnaces  for  the  wood  are  introduced  on  op- 
posite sides  of  ihe  shaft,  saving  v        ixes  on  the  same  diame- 


HYDKAULIC  CEMENTS,  AND  MOETAES. 


143 


ter.  On  a  third  side  is  placed  the  liole  for  drawing  the  burnt 
lime. 


Fig.  26.  Fig.  27 


253.  In  burning  in  any  perpetual  wood-burning  kiln,  it  is 
essential  that  the  draw-hole  be  kept  tightly  closed,  except  while 
drawing  the  burnt  lime,  and  to  regulate  the  draught  entirely  by 
the  furnace  doors. 

254.  Soft  wood  is  used  for  lime-burning  in  Ilockland,  such  as 
hemlock,  pine,  spruce,  and  fir.  About  four  cords  (of  128  cubic  / 
feet  each)  are  required  to  burn  one  hundred  barrels  of  lime,  of 
230  to  240  pounds  each.  This  is  a  saving  of  about  f  of  the 
fuel,  as  compared  with  the  consumption  of  intermittent 
kilns. 

255.  When  first  starting  the  kiln,  the  portion  below  the 
level  of  the  grate,  called  the  thimble,  is  filled  with  light-wood. 
The  interior  of  the  kiln,  nearly  up  to  the  top,  is  also  lined  with 
w^ood  one  stick  deep,  set  up  on  end.  These  precautions  are 
necessary,  first,  because  the  stone  on  a  level  with,  as  w^ell  as 
below  the  grates,  would  otherwise  be  insufficiently  burnt ;  and, 
second,  because  the  expansion  of  the  stone,  when  heated,  would 
injure  the  kiln,  if  the  latter  was  compactly  filled. 

The  stone  for  burning  is  generally  broken  into  pieces  of 
various  sizes,  not  exceeding  ten  inches  cube. 

256.  A  kiln  holding  enough  stone  to  make  175  barrels  of 
lime  w^ll  yield,  after  being  started,  about  100  barrels  every 
twenty-four  hours.  The  stone  is  exposed  to  the  heat  from 
forty-two  to  forty-eight  hours.    The  lime  is  drawn  every  six  oi 


144 


PRACTICAL  TREATISE  ON  LIMES, 


eight  hours,  and  oftener,  if  the  capacity  of  the  thimble  is  rather 
restricted. 

257.  Moist  limestone  is  said  to  burn  more  readily  than  that 
which  is  dry,  a  circumstance  which  is  explained  by  the  fact 
that  the  presence  of  aqueous  vapor  not  only  offers  no  obstacle 
t\j  the  evolution  of  carbonic  acid,  but  in  reality  mechanically 
aids  the  escape  of  that  gas. 

258.  The  great  number  of  trials  which  have  been  made  with 
the  cement  stones  from  different  parts  of  the  country,  within 
the  last  two  years,  by  subjecting  them  to  every  conceivable 
degree  of  calcination,  point  so  uniformly  to  the  necessity  of 
Undoubted  no  exercising  the  utmost  care  in  conducting  this 
cessity  of  careful     delicate  operation  on  a  large  scale,  that  it  is  im- 

possible  to  gainsay  its  importance.  They  also 
establish  beyond  a  doubt  the  magnitude  of  the  error  committed 
by  manufacturers,  in  mingling  the  different  varieties  of  stone 
together  in  burning.  A  few  of  the  results  will  be  briefly  no- 
ticed, somewhat  in  detail. 

259.  The  stone  from  Eockbridge  county,  Virginia,  from 
which  the  James  River  cement  is  manufactured,  was  broken 

Stone  from  James     ^^^^  P^^^^^       ^^^^^  *  ^^^^  ^^b^' 

River  Cement  cined  at  a  bright  red  heat,  for  periods  varying 
from  thirty-five  minutes  to  eight  hours.  It  re- 
quired three  hours  to  expel  all  the  carbonic  acid  gas,  below 
which  point,  all  the  samples  gave  a  quick  and  energetic  cement, 
which  hardened  readily  under  water,  without  being  subse- 
quently thrown  down.  The  pieces  burnt  for  thirty-five  min- 
utes and  one  hour  respectively,  were  both  partially  raw  inside. 
After  three  hours'  burning,  a  rapid  destruction  of  hydraulic 
energy  ensued,  w^hich  was  in  no  degree  restored  when  the  heat 
was  continued  to  eight  hours.  At  this  point,  though  not  below 
it,  some  portions  of  the  stone  showed  evidences  of  partial  vitrifi- 
cation. For  analysis  of  this  stone,  see  Table  lY.  "  The  James 
Hiver  cement,"  as  prepared  for  market,  effervesces  briskly  with 
dilute  hydrochloric  acid,  and  will  indurate  under  water  at  65o 


HYDRAULIC  CEMENTS,  AND  MORTAES.  145 


F.,  in  four  to  five  minutes,  and  in  six  to  eight  minutes,  so  as  to 
support  the  light  and  the  heavy  testing-wires,  respectively. 

260.  At  Point-aux-Koches,  Lake  Champlain,  a  good  cement 
stone  is  found,  which  will  sustain,  without  injury,  a  somewhat 
longer  calcination  than  that  from  Virginia.  It  has  never 
been  used  for  cement,  but   when  properly 

burnt,  will  compare  favorably  with  our  best  Roch^er.^^^*^"^" 
cements,  in  hydraulic  activity. 

261.  Some  of  this  stone  was  broken  up  and  burnt  as  before, 
samples  being  removed  from  the  fire  at  periods  of  1,  2,  3,  4,  5, 
6,  and  7  hours,  respectively.  It  required  6  hours  to  expel  the 
last  traces  of  carbonic  acid  gas.  All  the  samples  set  readily 
both  in  the  air  and  in  water.  That  which  had  received  seven 
hours'  burning,  however,  even  when  allowed  to  harden  in  the 
air  considerably  longer  than  was  necessary  to  support  the 
heavy  testing  wire,  would  not  bear  immersion,  but,  after  fifteen 
to  twenty  minutes,  was  reduced  to  the  condition  of  soft  paste. 
For  analysis  of  this  stone,  see  Table  lY. 

262.  Two  pieces  of  stone,  from  Lockport,  !Nr.  Y.,  were  sent 
for  trial,  the  composition  of  both  being  almost  identical.  They 
are  argillaceous  limestones  strictly  speaking,  and  contain  no 
magnesia.    For  their  analysis,  see  Table  lY. 

The  natural  color  of  this  stone  is  a  grayish  blue,  the  texture 
granular ;  the  first  specimen  was  fine  grained,  the  second 
rather  coarse.  Both  were  subjected  to  calcination  in  a 
crucible,  samples  being  removed  for  trial  at  the  expiration 
of  the  first  half  hour  of  brip-ht  red  heat,  and 

,      ^         ,  .         From  Lockport, 

subsequently  at  intervals  of  one  hour,  allowing    k  Y. 
nine  hours  to  the  last  portions. 

263.  Of  the  ^r^^  specimen,  all  the  burnings  set  rapidly  in 
the  air,  but  none  of  them  perfectly  sustained  subsequent  con- 
tinued immersion  in  water,  except  the  three  corresponding  to 
one-half  hour's,  two  hours',  and  nine  hours',  calcination.  The 
sample  burnt  eight  hours  did  not  fall  entirely  to  pieces  on  im- 
mersion, but  swelled  slightly  and  was  soon  covered  with  sev- 

10 


14(3 


PRACTICAL  TREATISE  ON  LIMES, 


ei-al  deep  cracks  on  the  upper  and  lateral  surface,  in  whicli  eoni' 
dition  it  continued  to  indurate  in  a  satisfactory  manner,  and 
underwent  no  furtlier  change.  The  trials  with  this  stone  de- 
veloped some  novel  and  exceptional  properties.  Among  the 
several  stages  of  calcination  through  which  it  passed  success- 
ively, there  were  exhibited  three  points  of  maximum,  and  two 
of  minimum,  hydraulic  energy.  The  two  minima  are  found  on 
either  side  of  the  sample  burnt  two  hours,  while  the  three  max- 
ima correspond  with  the  samples  burnt  one-half  hour,  two  hours, 
and  nine  hours,  respectively.  In  mixing  with  water,  a  consider- 
able elevation  of  temperature  was  exhibited  by  all  the  burnings. 
By  working  the  paste  over  with  the  trowel  as  long  as  it  remains 
warm,  or  by  reworking  it  after  it  has  commenced  to  swell  and 
crack,  it  loses  the  objectionable  and  characteristic  properties  of 
the  intermediate  limes,  and  will  retain  its  form  in  water  ;  but  is, 
at  the  same  time,  degraded  in  hydraulic  power  to  a  level  with 
the  eminently  hydraulic  limes.  The  portion  burnt  nine  hours 
turned  a  dark  bluish  green  color,  a  few  hours  after  it  had  been 
immersed  in  water.  This  may  be  due  to  the  carbonate  of  the 
protoxide  of  iron  present  in  the  raw  stone,  which  parts  with 
its  carbonic  acid  gas  after  a  long  exposure  to  heat.  The  pro- 
toxide thus  formed  would  turn  green  by  the  absorption  of 
water,  becoming  the  hydrated  protoxide  of  iron  (FeO  +  HO). 
Tho  green  color  is  readily  driven  off  by  heat.  A  more  probable 
hypothesis  appears  to  be,  that  it  is  the  peroxide  (FcgOg),  which 
is  present  in  the  raw  stone.  This,  losing  a  portion  of  its  oxy- 
gen at  a  high  temperature,  is  converted  by  a  new  combination 
of  its  elements  into  the  magnetic  oxide  (Fes04),  a  substance 
known,  under  certain  conditions,  to  possess  the  properties  of 
the  pozzuolanas.  This,  however,  does  not  account  for  the 
change  in  color. 

264.  The  curves  of  the  diagram,  Fig.  28,  will  perhaps  illus- 
trate the  peculiarities  developed  during  the  calcination  more 
prominently  than  a  written  description  can.  Let  o  be  the  ori- 
gin of  co-ordinate,  and  the  horizontal  and  vertical  lines  through 


HYDRAULIC  CEMENTS,  AND  MOKTAES.  147 


'fzTir  1  2  5  4  5  6  7  8  9 


2 

o' 

JfS 

/L 

^  .  . 

i 
f 

+(-+t- 

i 
i 

^  - 

1 
2 

Fig.  28. 


6>  the  axes  of  abscissas  and  ordinates  respectively.  From  o 
lay  off  on  (9,  d  distances  proportional  to  the  several  degrees  of 
calcination,  as  determined  by  the  duration  of  the  heat.  These 
distances  are  marked  on  the  top  horizontal  line  for  every  half 
hour,  up  to  nine  hours.  On  the  perpendiculars,  through  the 
points  thus  determined,  lay  off  distances  from  the  line  o,  o\ 
that  shall  represent  the  hydraulic  activity  of  the  cements  at 
the  several  stages  of  burning.  These  are  positive  ordinates, 
and  lie  above  the  line  o,  o' .  The  absence  of  hydraulic  activity 
capable  of  sustaining  immersion,  or  in  other  words,  the  rela- 
tive rapidity  with  which  the  paste  yields  to  the  solvent  action 
of  water,  is  represented  by  nesrative  ordinates  ^ 

'         ^  /  .        Curves  of  energy 

below  the  line  (9,  d  ;  the  line  o,  o',  therefore,  in-  of  certain  Ameri 
dicates  the  points  of  hydraulic  equilibrium,  so  cements, 
to  speak,  at  which  the  cements  either  part  with  or  resume  the 
power  of  "  setting"  under  water,  if  immersed  in  the  state  of 
paste.  A  Gurve  traced  through  the  several  points  obtained 
with  a  single  cement,  is  called  the  curve  of  energy  of  that  ce- 


148 


PEACTICAL  TREATISE  ON  LIMES, 


ment.  The  cements  which  furnished  the  curves  of  Fiii.  28. 
were  from  the  following  localities  : 

No.  1.  Cement,  from  Loci  port,  N.  T.,  first  specimen. 
No.  2.       "       "  "  second  do. 

No.  3.       "       **     centre  of  Round  Top  Quarry,  near  Hancock,  Md. 
No.  4.       "       "     Stratum  No.  15  of  paragraph  21,  from  High  Falls,  Ulstei 
county,  N.  Y. 

No.  5.       "       "     Balcony  Falls,  Rockbridge  county,  Ya. 
No.  6.       "       *'     Point-aux- Roches,  Lake  Champlain. 

No.  T.       "       "     Stratum  No.  1,  from  Martin  &  Clearwater's  Quarry,  Ulster 
county,  N.  Y. 

No.  8.       "       "     Stratum  No.  3,  from  Martin  &  Clearwater's  Quarry,  Ulster 
county,  N.  Y. 

265.  Ohservations  on  Fig.  28. — By  examining  the  curves 
derived  from  the  two  specimens  of  Lockport  cement,  it  is 
seen  that : 

Ist.  When  burnt  from  i  to  f  of  an  hour,  both  will  set  under 
water,  and,  in  combination,  would  therefore  make  a  good  ce- 
ment when  thus  treated. 

2d.  Between  f  of  an  hour  and  \\  hours'  calcination,  the 
Observations  on  ^'^^  under  water,  while  the  second 

diagram.  Fig.  28.  will ;  and  the  properties  of  the  combination 
would  depend  on  the  proportion  adopted. 

3d.  Two  hours'  burning  exactly  reverses  this  state  of  things, 
the  first  setting  under  water,  while  the  second  will  not,  and 
this  condition  obtains  until  the  calcination  is  continued  for  ?>\ 
hours. 

4th.  Beyond  this  point,  neither  will  set  under  water,  until 
a  calcination  of  7^  hours  is  reached,  when  the  first  resumes 
its  hydraulic  action,  and  continues  so,  the  second  remaining 
as  before. 

As  there  is  no  greater  diversity  among  the  eight  varieties  of 
cement  represented  in  diagram.  Fig.  28,  than  is  ordinarily  to 
be  found  in  the  several  layers  of  the  same  quarry,  which,  ac- 
cording to  the  usual  custom,  are  burnt  together,  we  can  to 
some  extent  realize,  by  an  inspection  of  the  diagram,  the 
practical  effect  of  the  system  now  in  vogue  among  manufac- 
turers. 


iryDEAULIO  CEMEOTS,  AND  MOETAES. 


149 


5th.  All  the  eight  varieties,  burnt  from  ^  to  f  of  an  hour, 
set  under  water,  and  when  thus  treated,  would  make  a  quick 
setting  combination.  This  corresponds  with  the  well-known 
fact  that  the  subcarbonates  are  very  actively  hydraulic. 

6th.  Calcined  two  hours,  four  of  them  set  well  under  water, 
and  four  do  not. 

7th.  Burnt  four  and  a  half  hours,  three  of  them  set  under 
water,  and  five  do  not. 

8th.  Burnt  six  and  a  half  hours,  only  two  of  them  set  under 
water,  (and  one  of  these  two  rather  sluggishly),  while  six  do 
not.  Of  these  latter,  however,  No.  4  and  'No.  2  may  be  re- 
garded as  intermediate  limes ;  while  JSTo.  7  and  No.  1  are  inter- 
mediate limes  at  some  stages  of  calcination,  and  ordinary  hy- 
draulic limes,  apparently,  at  others.  For  remarks  on  the  stone 
which  furnished  curve  No.  4,  see  paragraph  21,  w^here  it  de- 
scribes layers  nine  to  sixteen  inclusive,  of  the  deposit  in  Ulster 
Co.,  N.  Y. 

9th.  Burnt  eight  hours,  the  specimens  are  again  equally  di- 
/ided,  that  is,  four  of  them  will  bear  immersion  in  water,  and 
'bur  will  not. 

10th.  It  is  evident  that  the  quickest  setting  combination  of 
the  eight  varieties  of  stone,  would  be  secured  by  burning  them 
separately,  to  that  degree  indicated  by  the  highest  point  in 
their  respective  curves;  wlJle  the  combination  least  likely  to 
sustain  immersion,  would  in  like  manner  correspond  with  the 
lowest  points  in  the  curves. 

11th.  Inasmuch  as  the  quickest  setting  cements  do  not 
always  give  the  strongest  mortars,  while  slow  setting  ones  may 
excel  in  that  respect,  it  may  be  inferred  that  curves  which 
would  represent  the  degrees  of  calcination  corresponding  to  the 
several  degrees  of  strength  of  cement  gangs,  varying  with  and 
dependent  on  the  calcination,  might  difier  very  materially  from 
those  given  in  the  diagram,  which  have  especial  reference  sim- 
plj'  to  the  hydraulic  activity  of  the  gangs,  when  immersed  in 
the  state  of  paste.    Such  mii*ves  of  strength  could  readily  be 


150  PRACTICAL  TEEATISE  ON  LIMES, 

constructed,  however,  by  making  mortar  prisms  of  the  pro 
ducts  obtained  at  the  several  stages  of  calcination,  and  sub- 
jecting them  to  the  usual  breaking  test.  Such  a  diagram, 
comprehending  all  the  dissimilar  layers  of  a  cement  deposit, 
and  corrected  from  time  to  time,  as  often  as  the  changeable 
character  of  the  rock  might  require,  v^ould  furnish  the  only 
unerring  guide  to  a  proper  calcination  of  the  stone  of  the 
quarry. 

12th.  As  all  the  specimens  subjected  to  nine  hours'  burning 
liad  parted  v^ith  the  whole  of  their  carbonic  acid,  while  some 
of  tliem  reached  the  same  condition  in  a  much  shorter  space  of 
time,  it  follows  that  M.  Petot's  deduction,  that  cement  stone 
at  the  point  of  complete  calcination"  gives  *'  a  substance  near- 
ly inert,"  is  by  no  means  correct  as  a  principle,  but  is  only  an 
improper  generalization  of  results  obtained  in  a  particular  case  ; 
for  the  diagram  shows  that  at  every  stage  of  the  burning, 
some  of  the  curves  lie  above  the  zero  line,  and  therefore  repre- 
sent more  or  less  energetic  cements.  It  is  true  that  at  six 
and  a  half  hours'  calcination,  six  curves  out  of  the  eight  lie 
below  that  line,  and  might  therefore,  relatively  speaking,  be 
said  to  represent  "  inert  substances ;"  but  with  this  exception, 
every  stage  of  burning  gives  active  cements  from  about  one- 
half  of  the  specimens  under  trial,  while  one  specimen  from 
the  Round  Top  quarry  (curve  No.  3)  was  quick  and  energetic 
at  every  stage,  after  the  first  twenty  minutes. 

266.  "We  cannot  do  better  perhaps  in  this  connection,  than  to 
give  a  diagram  of  the  curves  of  energy  of  several  calcareous 
substances,  as  constructed  by  M.  Petot.  We  know  from  the 
foregoing  discussion  that  the  one  representing,  or  said  to  repre- 
sent, hydraulic  cement  (plastic  cement,  as  it  is  therein  termed), 
must  refer  to  a  particular  case  only.  It  is  possible  that  the 
others  do  also.  M.  Petot  does  not  inform  us  on  this  point,  and 
our  experiments  have  not  extended  far  enough  to  enable  us  to 
speak  with  confidence  on  the  subject.  The  curves  are  indi- 
cated in  the  diagram.  Figure  29. 


151 


7^ 

Tlie  numbers  on  the  lower 
;i  -rizontal  line  (marked  zero 
I'lJc'),  represent  the  distances 
from  the  o  point,  propor- 
tional to  some  of  the  princi- 
pal degrees  of  torref action. 


Fig.  29. 

No.  1  corresponds  to  the  degTee  of  moderate  burning  of  bricks. 
No.  2  "  '*         thorough     "       "  " 

No.  3       "  "         "        complete  calcination  of  fat  lime. 

No.  4       "  "  "        super-calcination  of  fat  lime. 

On  the  perpendiculars  through  these  points,  distances  are 
laid  off,  above  the  zero  line  proportional  to  the  hydraulic  energy 
of  each  particular  product,  at  the  several  stages  of  calcination 
respectively.  The  curves  of  energy  are  the  lines  drawn 
through  the  points  thus  determined.  A  total  want  of  hydrau- 
lic energy  is  indicated  when  the  curve  lies  on  the  zero  line. 

Curve  No.  1  belongs  to  fat  lime. 

"       "  2       **     "  hydraulic  lime. 

"       "  3       "     "       "       (or  plastic)  cement. 

"       "4  u  calcareous  clays  suitable  for  pozzuolana. 

*'       "5       "     "  clays  not  calcareous. 

267.  In  the  absence  of  any  information  as  to  the  method  pur- 
sued in  obtaining  these  curves,  and  knowing  from  our  trials  that 
curve  Ko.  3,  said  to  represent  cement  stone  as  a  class,  does  not  so 
represent  it,  and,  in  all  probability,  was  obtained  from  a  single 
sample,  it  seems  safe  to  infer,  that  M.  Petot  restricted  his  inves- 
tigations of  the  other  substance  to  individual  specimens  also. 
"With  the  exception  of  fat  lime,  it  is  believed  that  all  the  sub- 
stances which  he  tried,  represented  in  Figure  29,  might  be  ex- 
pected to  produce  curves,  as  dissimilar  in  character  as  those 
obtained  for  American  cements. 

268.  It  would  appear,  from  the  results  given  above,  that 

the  hydraulicity  of  cements  derived  from  the    Capricious  varia- 

T    ,       .  ,  .  1      .     n  during 

same  quarry  and   bearmg  almost  identically  calcination. 


152 


PRACTICAL  TREATISE  ON  LIMES, 


the  same  composition,  is  subject  to  singular  and  apparently 
capricious  variations  during  the  progress  of  calcination.  Al- 
though the  diagram.  Figure  28,  does  not  exhibit  the  charac- 
teristic peculiarities  in  this  respect  of  all  the  individual  layers 
of  any  one  quarry,  experiments  to  elucidate  this  feature 
have  been  carried  on  with  considerable  minuteness  of  detail, 
and  show  quite  conclusively  that  the  principal,  and  it  may  be 
said,  the  only  cause  of  the  frequent  failure  to  attain  uniform 
results  by  any  known  method  of  calcination,  lies  in  the  obscure, 
because  unstudied  changes  in  hydraulic  character,  through 
which  the  stone  successively  passes  during  the  burning.  There 
are,  it  is  true,  many  layers  of  stone  that  yield  a  really  good  and 
c,  ,         energetic  cement  at  any  and  all  stages  of  cal- 

Some  cements  are  o  J  t> 

good  at  all  stages  cination  between  the  points  of  half  calcination 
and  complete  vitrification ;  and  it  luckily  so  hap- 
pens, so  far  as  recent  observation  teaches,  that  this  kind  of 
stone  is  very  extensively  distributed  throughout  the  country, 
and  comprises  at  least  one-half  of  the  thickness  of  the  deposits 
to  which  w^e  now  look  for  our  supply,  viz.  :  those  in  Ulster 
county,  "New  York,  and  on  the  Potomac  and  James  Rivers  in 
Maryland  and  Virginia.  The  negative  character  of  some  of 
the  other  contiguous  layers  of  these  deposits,  as  well  as  the 
positively  injurious  character  of  many,  or  rather,  the  indiffer- 
ently good  as  well  as  the  really  bad  cement  obtained  by  an 
They  redeem  the  injudicious  calcination  of  them,  is  thereby  par- 
defects  m  others,  tially  redeemed,  or,  in  a  measure,  counteracted, 
as  it  is  the  average  aggregate  result  we  obtain  in  all  cases  in 
practice. 

269.  JSTot  unfrequently,  as  before  remarked,  the  changeable 
Cements  act  like  cements,  as  they  may  be  termed,  when  burnt  to 
Um^sTt^certain  ^  certain  point,  possess  in  a  marked  degree  all 
stages  of  burning,  the  objectionable  properties  of  the  intermediate 
limes,— setting  rapidly  when  first  mixed  into  a  paste,  and  im- 
mersed in  water,  but  possessing  no  permanence  or  stability ; 
while  sometimes  above  and  sometimes  below  this  point,  and 


HYDEAULIC  CEMEOTS,  AND  MOETAES.  153 


often  both  above  and  below  it,  a  2:ood  cement  is        .  , 

'     *  Maximum  and 

produced.    At  other  times  this  condition  of   minimum  hydrau- 

things  is  reversed,  there  being  but  one  point  of  ^^^^^^ 

maximum,  while  there  are  two  of  minimum  hydraulicity. 

Sometimes  the  substance  conducts  itself  like  imperfectly  slaked 

common  lime,  and  begins  to  swell  up  and  soften  the  moment  it 

is  immersed,  possessing  not  even  the  dangerous  energy  of  the 

intermediate  type;  at  others  again,  it  appears  to  be  almost 

entirely  inert,  like  clay.    The  influence  which  these  changes 

exert  on  the  stren2:th  and  hardness  of  the  result-    ^,  , 

o  These  changes 

ing  cement,  presents  a  subject   for  serious    caU  for  serious 

mi  •    •  1  •  1  inquiry. 

inquiry.     lhat  those  varieties  which,  at  any 
stage  of  calcination,  give  intermediate  limes,  should  be  either 
burnt  by  themselves,  and  with  extra  care,  or    Cements  that  can 
else  carefully  excluded  from  the  combination,    produce  interme- 

,  -  ^  ^  ,     -  -  diate  limes  to  be 

there  would  appear  to  be  no  doubt ;  unless,    burnt  by  them- 
indeed,  the  precaution  is  taken  to  manufacture    some  time  before 
and  store  them  in  bulk,  several  months  before  use. 
they  are  used.    This  is  believed  to  be  a  specific  remedy  for  the 
defects  which  belong  to  this  type  of  cements.    It,  however, 
degrades  them  in  hydraulic  energy,  as  well  as  in  strength  and 
hardness,  to  a  level  with  ordinary  hydraulic       .  ^.  , 

'  «^  Objections  to  the 

limes.    'No  adequate  trials  of  strength  have  last-mentioned 

T        .  -,  ^    T  .    .         1.1  precaution. 

been  made  with  any  oi  those  varieties  which, 

at  any  stage  of  calcination  below  that  of  incipient  vitrification, 

part  entirely  with  the  power  of  sustaining  immersion  in  water. 

270.  The  results  given  in  Table  YI.  were  obtained  with 
Layer  ISTo.  12  of  the  deposit  at  High  Falls,  Ulster  county. 
The  table  contains  four  kinds  of  cements  designated  sever- 
ally, Number  One,  N^umber  Two,  ISTumber  Three,  Number 
Four.    They  were  obtained  by  burninsr  the 

-n  ,  .,  ^        ,  Trials  with  Layer 

stone  m  a  small  kiln,  about  seven  feet  deep  and    No.  12,  Ulster 
twenty  inches  to  twenty-four  inches  in  diam- 
eter,  called  a  "  try  "  kiln,  and  subsequently  separating  the  burnt 
stone  into  four  portions,  differing  from  each  other  in  the 


154 


PRACTICAL  TREATISE  ON  LIME», 


degree  of  calcination  which  they  had  respectively  attained. 
These  after  being  ground,  were  passed  through  wire  sieve  No. 
80,  in  order  to  secure  a  uniform  degree  of  pulverization. 

271.  Numlxir  One  was  underburnt  stone ;  the  fragments, 
when  broken  open,  showed  a  raw  core,  in  the  centre,  of  the 
natural  color  of  the  stone,  though,  on  the  exterior,  they 
presented  the  appearance  of  having  been  sufficiently  calcined. 

In  the  ordinary  process  of  manufacturing 
SiclftS''^  cement,  nearly  all  this  variety  is  used.  The 
.  only  precaution  usually  observed  is  to  exclude 
those  portions  that  might,  on  account  of  their  hardness, 
endanger  the  safety  of  the  machinery  in  grinding.  In  assort- 
ing the  burnt  stone,  it  is  readily  distinguished  by  its  greater 
specific  gravity. 

272.  Wwnber  Two  was  selected  by  an  experienced  burner,  as 
the  inferior  limit  of  complete  calcination.    ISTone  of  the  frag- 
ments contained  a  raw  core,  and  none  showed 

Sldnation^^  J  vitrification  on  the  exterior.  They  effervesced 

with  dilute  hydrochloric  acid  very  slightly. 

273.  Number  Three  was  well  burnt,  and  was  selected  to 

represent  the  superior  limit  of  complete  cal- 
calcination^  ci nation.    All  the  carbonic  acid  gas  was  ex- 

pelled, but  no  vitrification  had  taken  place. 

274.  Number  Four  was   overhurnt  and  vitrified  stone, 

commonly  called  "  cinders  "  by  the  workmen. 
Sdnatfon^*^         ^  small  proportion  only  of  this  variety  finds  its 

way  into  the  cement  manufactured  for  market. 
From  its  extreme  hardness,  a  due  regard  to  wear  and  tear  of 
machinery  suggests  its  careful  exclusion.  It  usually  occurs  in 
masses  that  are  glazed  over  and  run  together,  and  it  is  easily 
distinguished  from  the  other  portions  of  the  kiln. 

275.  TABLE  YL 

Showing  the  effect  of  different  degrees  of  calcination, 
on   the  quality  of  hydraulic   cement.    The   mortars  were 


HYPKAULIC  CEMENTS,  AND  MOETAES. 


155 


in  the  form  of  rectangular  parallelopipeds,  2"  x  2"  X  8", 
which  had  set,  under  a  pressure  of  32  lbs.  per  square  inch. 
They  were  allowed  to  harden  one  day  in  the  air,  and  were 
then  kept  in  sea-water.  They  were  broken  on  supports  four 
inches  apart  by  a  force  applied  at  the  middle.  In  all  cases,  the 
composition  of  the  mortar  was  cement  powder  1  vol.,  sand  2 
vols. ;  age  of  mortars,  95  days. 


Kind  of  cement.   It  was  all  derived  from  Layer  Number 
Twelve,  Ulster  County,  N.  Y. 


Number  One,  underbumt. 


Number  Two,  inferior  limit  of  complete  calcination. , 


Number  Three,  superior  limit  of  complete  calcination 


Number  Four,  vitrified. 


216 
204 
189 
181 
300 
246 
248 
26.3 
204 
209 
203 
209 
209 
213 
197 
275 
281 
298 
326 
348 
353 
263 
259 
267 
211 
259 
255 
82 
88 
79 
73 
83 
86 
79 
76 


156 


PPvACTICAL  TEEATISE  ON  LIMES, 


Ohservations  on  Tabh  VI. — The  cements  were  fresh  from 
the  kiln.  IN^umber  One  possessed  the  greatest  degree  of 
hydraulic  activity,  and  required  but  ten  or  twelve  minutes  to 
set  under  water,  so  as  to  support  the  light  testing  wire. 
Number  Two  required  twenty-five  minutes ;  Number  Three, 
rhirty  to  thirty-five  minutes;  and  Number  Four,  ninety  to 
one  hundred  minutes,  to  attain  the  same  degree  of  induration. 
Similar  results,  as  regards  simply  the  superior  promptness  of 
the  initial  energy  of  underburnt  cements,  were  obtained  with 
other  strata  from  the  same  locality,  as  well  as  with  stone  from 
the  Potomac  and  James  Rivers.  Each  cement  has,  however, 
beyond  the  stage  of  incomplete  calcination,  its  marked  pecu- 
liarities of  strength  and  hydraulic  activity. 

276.  This  property  is  so  universal,  that  even  common  fat  lime 

may  be  rendered  moderately  hydraulic,  and  the 
Uy  of^under^*^^'  ii^itial  energy  of  hydraulic  limes  considerably 
burnt  limes  very  increased,  by  suitable  underburning.  This  in- 
creased activity,  however,  does  not  appear  to  be 
accompanied  by  a  corresponding  augmentation  of  the  strength 
of  the  resulting  paste,  especially  in  the  genuine  cements,  as  seen 
by  Table  YI. 

277.  After  the  mortars  of  the  foregoing  table  were  mixed,  the 
balance  of  the  four  varieties  of  cement  was  carefully  preserved 
in  a  dry  room  for  subsequent  trial.    At  the  end  of  six  months, 
other  prisms  were  made  of  the  cement  paste  without  sand 
The  results  are  given  in  the  following  table : 

TABLE  YII. 

Showing  the  breaking  weight  of  rectangular  parallelepipeds 
(2^'  X  2^'  X  8'^)  of  pure  cement  mixed  stiff,  of  different  de- 
grees of  calcination,  broken  on  supports  four  inches  apart  by 
a  pressure  at  the  middle.  The  mortars  "  set"  under  a  pressure 
of  thirty-two  pounds  per  square  inch,  and  were  put  in  sea-water 
when  one  day  old.  and  kept  there  until  broken,  at  the  age  of 


HTDRAULIC  CEMENTS,  AND  MOKTAES. 


157 


ninety-five  days.  The  cement  was  measured  by  volume  of 
powder. 


Kind  of  cement. 


Penetration  of 
point  in  inches. 


g  «  o 

its 


Number  One,  underburnt. 


Numbe'-  Iwo,  inferior  limit  of  complete  calcination. . 

•  U  t(  (I 

(i  tl  It  (I 

Number  Three,  superior  limit  of  complete  calcination, 
u  n  ti  n 

Number  Four,  vitrified  


.097 
.107 
.106 
.195 
.075 
.050 
.050 
.060 
.130 
.100 
.150 
.106 
.090 
.090 


.170 
.187 
.187 
,182 
.127 
.100 
.100 
.112 
.230 
.170 
.260 
.170 
.150 
.165 


615 
689 
621 
542 
519 
689 
662 
546 
443 
863 
595 
918 
894 


-654  lbs 

608  " 
494  " 

817  " 


The  results  given  in  Table  YII.  were  so  difierent  from  those 
obtained  for. Table  VL,  in  the  character  assumed  by  the  vitrified 
cement,  that  other  trials  were  made  with  the  same  kind  of 
stone  in  order  that  all  doubts,  as  to  the  relative  value  of  the 
products,  derived  at  the  several  stages  of  calcination,  might,  if 
possible  be  removed.  The  same  sized  parallelepipeds  (2"  X 
2"  X  8")  were  made  without  pressure  (some  with  and  some 
without  sand).  These  were  put  in  sea-water  when  one  day  old, 
and  kept  there,  until  broken  at  the  age  of  sixty  days,  the  sup- 
ports, as  usual,  being  four  inches  apart.  Several  trials  gave 
the  following  average  results.  The  cement  was  measured  by 
volume  of  dry  powder. 

TABLE  YIII. 


No.  of  ce- 
ment. 

Degree  of  caleination. 

Breaking  weight  of 
prisms  of 

Cfment  with- 
out sand. 

Cement,  1. 
Sand,  2. 

1 

2. 
4 

557  lbs 
646  " 
513  " 
670  " 

190  lbs. 

224  *' 
143  " 
237  " 

Number  Two,  inferior  limit  of  complete  calcination 
Number  Three,  suuerior  limit  of  complete  calcination 

278.  Ohservations  on  Tables  VL,  YIL,  and.  YTIL—Vcl^  dis- 


158 


PEACTICAL  TREATISE  01^  LIMES, 


crepancies  between  the  breaking  weights  of  Number  Four  (vit- 
rified cement)  in  the  three  Tables,  appear  irreconcilable  on  any 
other  supposition  than  that  of  error  in  recording  the  results  of 
Table  YL  It  is  possible  that  cements  I^umber  Three  and  ISTum- 
ber  Four,  may  have  been  exchanged  accidentally  while  making 
the  mortars  of  Table  YL  By  making  this  transposition  in 
Table  YL,  that  is,  by  exchanging  the  names  of  cements  Num- 
ber Three  and  Number  Four;  the  results  of  the  last  three  tables 
pre  more  readily  comprehended,  cement  Number  Four  giving 
the  strongest  of  the  four  mortars  in  each  case,  and  cement 
Number  Three,  the  weakest. 

279.  We  will  now,  as  a 
matter  of  interest,  con- 
struct, in  the  manner  in- 
dicated in  the  11th  obser- 
vation on  Fig. 

Sgth.     28,  the  curve  of 
strength  of  the 
cement  used  for  Tables 
YL,  YIL,  and  YIIL,  bas-  Fig.  so. 

od  on  the  several  progressive  stages  of  calcination,  as  described 
in  paragraph  266,  and  the  breaking  weights  given  in  the  three 
tables. 

280.  These  breaking-weights  were  obtained  under  four  vary- 
ing conditions,  as  regards  age  and  kind  of  mortar,  and  the 
curve  of  strength  for  each  is  given  in  Fig.  30. 

281.  These  conditions  (see  Tables  YL,  YIL,  and  YIIL,)  are : 


1st.  Cement  vol.  1,  sand  vol.  2 
2d.    Pure  cement 
3d.  Pare  cement    .       .  . 
4tli.  Cement  vol.  1,  sand  vol.  3 


Age  95  days,  gives  curve  No.  1 
Age  95  days,  gives  curve  No.  2. 
Age  60  days,  gives  curve  No.  3, 
Age  60  daya,  gives  curve  No.  4. 


282.  The  abscissas  are  laid  off  on  the  horizontal  line  from 
the  zero  point  to  the  numbers  1,  2,  3,  and  4,  in  lengths  corre- 
Bxplanationof  ^ponding  to  the  four  degrees  of  burning  (para- 
Figure  30.        graph  266).    On  the  ordinates  through  the  points 


HYDKAULIC  CEMEInTS,  AND  MOETAES.  159 


1,  2,  3,  and  4,  distances  proportional  to  the  strength  of  the 
prisms,  at  the  rate  of  100  lbs.  to  i  of  an  inch,  are  laid  off. 
The  points  thus  obtained,  fix  the  position  of  the  curve. 

283.  The  dotted  branch  a  h,  of  curve  No.  1,  corresponds  to 
results  given  in  Table  YI.,  on  the  supposition  that  they  are  there 
recorded  correctly,  while  the  full  branch  supposes  the  exist- 
ence of  the  error  already  referred  to  above,  to  wit,  that  the 
average  breaking  weights  of  mortars  from  cement  Number 
Four,  Table  VI.,  is  276  lbs.,  and  from  cement  Number  Three, 
82  lbs.  and  not  as  recorded. 

284.  The  fact  that  curves  Nos.  2,  3,  and  4  give  two  points  of 
maximum  strength,  while  curve  No.  1  does  not,  except  under 
the  supposition  of  error,  affords  a  geometrical  confirmation  of 
this  hypothesis. 

285.  We  have  not  constructed  the  curve  of  strength  of  any 
of  the  American  cements,  except  that  made  from  layer  No.  12 
of  the  Ulster  Co.,  N.  Y.,  deposit,  recorded  in  the  last  three 
tables,  and  illustrated  by  Fig.  30. 

286.  We  see  that  a  proper  treatment  of  this  stone  requires 
that  the  calcination  should  stop  at  or  below  the  inferior  limit 
of  complete  calcination,  or  be  carried  to  the  point  of  vitrifica- 
tion, and  that,  at  the  point  of  superior  limit  of  complete  calci- 
nation, and  just  before  vitrification  sets  in,  the 

mortars  are  deficient  in  strength.  The  impro-  ^sed^n  burnhig. 
priety  of  mixing  this  stone,  for  burning,  with 
another  differing  from  it  in  the  period  or  periods  of  time  neces- 
sary to  reach  the  maximuin  points  of  the  curve  of  strength ; 
or,  of  burning  many  kinds  of  stone  together,  whereby  several 
maxima  and  minima  of  strength  may  be  developed  simultane- 
ously, needs  no  comment. 

287.  If  the  layers  of  cement  rock  preserved  individually  a 
uniform  character  over  extensive  areas,  it  would  be  a  simple 
matter  to  test  them  all  in  the  manner  above  described,  con- 
struct their  respective  curves  of  strength,  and  establish  for  the 
manufacturers  the  necessary  rules  and  precautions  for  burning ; 


160  PRACTICAL  TREATISE  OTf  LIMBS, 

but  the  cliangeable  character  of  the  deposits  renders  such  a 
labor  necessarily  one  of  constant  recurrence,  and  one  of  the 
appropriate  duties  of  the  manufacturer  himself.  We  have 
not  therefore  undertaken  this  work,  except  so  far  as  seemed 
necessary  to  illustrate  the  subject. 

288.  The  cement  stone,  after  calcination,  is  reduced  to  pow. 
der  between  ordinary  millstones,  after  being  first  passed 
through  a  ''cracker,"  which  crushes  it  up  into  pieces  not  ex- 
ceeding the  size  of  a  pea  or  a  hazel-nut.  The  cracker  is  made 
of  cast  iron  (Figs.  31  and  32),  and  consists  es- 
sentially of  a  frustrum  of  a  solid  cone  called  the 
core,  working  concentrically  within  the  inverted 
frustrum  of  a  right  hollow  cone,  both  being  pro- 
vided on  their  adjacent  surface  with  suitable  Fig.  si. 
grooves  and  flanges  for  breaking  up  the  stone 
as  it  passes  down  between  them.  The  elements 
of  the  lower  portions  of  both  cones  make  a 
smaller  angle  with  the  common  axis  than  those 
pertaining  to  the  upper  portions,  with  a  view  to 
lessen  the  strain,  and  the  effects  of  sudden  shocks 
upon  the  machinery,  by  securing  a  more  gradu-  Fig.  32. 
al  reduction  of  the  stone  to  the  required  size.  These  lower 
portions  being  subject  to  very  rapid  wearing,  are  made  of 
chilled  iron,  and  are  moreover  cast  in  separate  pieces,  in  order 
that  they  may  be  replaced  by  new  ones,  as  occasion  requires. 
The  greatest  diameter  of  the  core  at  the  top,  including  the 
flanges,  is  9  inches,  at  the  bottom  5^  to  6  inches,  and  its  height 
is  15  to  16  inches.  The  diameter  of  the  shell,  measured  within 
the  largest  flanges,  is  14  to  15  inches  at  the  top,  and  5i  to  0 
inches  at  the  bottom,  a  trifle  greater  than  that  of  the  core  ;  its 
height  is  16^  to  18  inches.  One  cracker  of  this  size,  working 
with  a  velocity  of  80  to  85  revolutions  per  minute,  is  sufficient 
for  a  mill  grinding  250  to  300  barrels  per  day.  It  is  custom- 
ary to  provide  one  cracker  for  every  two  run  of  stone.  For 
the  cement  mills,  the  French  Burr  stone  is  generally  used  in 


HYDRAULIC  CEMENTS,  AND  MOETAES. 


161 


tr.LF  ronntry,  except  in  Ulster  county,  New  York,  where  the 
Shawangunk  conglomerate  or  grit  (Formation  TV.  of  Professor 
Rogers'  classification  of  the  Rocks  of  Pennsylvania  and  Vir- 
ginia) has  been  fomid  to  be  an  excellent  substitute.  In  the 
vicinity  of  High  Falls,  it  occurs  only  a  few  feet  below  the  ce- 
ment deposit,  and  in  Rochester  township,  a  few  miles  further 
west,  is  extensively  quarried  for  millstones.  These  are  of  va- 
rious sizes,  from  2-J  to  5  feet  in  diameter.  When  driven  with 
full  power,  one  run  of  the  largest  size  will  grind,  on  an  aver- 
age, 300  pounds  of  cement  (one  barrel)  in  four  minutes,  as  or- 
dinarily prepared  for  market,  or  in  six  minutes,  if  ground  ex- 
tra fine,  as  it  should  be.  To  carry  the  degree  of  pulverization 
beyond  a  certain  point  involves  a  consumption  of  either  power 
or  time  which  appears  to  be  strikingly  out  of  proportion  to  the 
results  secured  thereby.  For  example,  a  cement  of  which  85  per 
cent,  will  pass  a  fine  wire  sieve  of  6,400  meshes  to  the  superfi- 
cial inch  (No.  80),  cannot  be  ground  so  that  95  per  cent,  will  pass 
the  same  sieve  without  doubling  one  or  the  other  of  these  func- 
tions. This  accounts  for  the  fact  that  the  cements  sent  to 
market  are,  as  a  general  thing,  imperfectly  ground.  The  capa- 
city of  a  cement  to  receive  sand,  other  thins^s  ^ 

'  ^      Cement  apt  to 

being  equal,  varies  directly  with  its  degree  of   be  ground  too 
fineness,  which  is,  therefore,  for  this  reason,  an 
important  consideration  to  consumers  to  say  nothing  of  other 
advantages  secured  by  approximating  to  an  impalpable  powder. 
Not  more  than  8  per  cent,  of  a  cement  should  be  rejected  by 
a  sieve  of  6,400  meshes  to  the  square  inch. 

289.  In  practice,  one  solid  cubic  yard  of  raw  stone  is  found 
to  yield  an  average  of  2,700  lbs.  or  nine  barrels  of  cement,  ex- 
clusive of  those  portions  rejected  in  assorting  the  burnt  stone. 

290.  The  Rosendale  cements  are  packed  in  barrels  from  the 
mill-spout  as  fast  as  ground.  In  Virginia,  the  custom  prevails 
of  storing  the  ground  element  in  bulk,  until  sent  to  market,  a 
practice  which,  besides  involving  additional  expense,  injures 
the  hydraulic  quickness  and  energy  of  all  cements,  except. 

11 


162 


PEACTICAL  TREATISE  ON  LIMES, 


those  containing  too  much  free  lime,  or  which  border  on  the 
intermediate  limes.  The  objectionable  properties,  in  such  cases, 
disappear  in  time,  but  invariably  at  the  expense  of  the  hydraul- 
icity.  It  must  be  admitted  that  there  are  very  few  quarries  in 
this  country,  that  do  not  assume  such  a  character  at  times,  that 
the  cements  are  of  better  quality,  and  may  be  more  safely  used 
by  ordinary  mechanics  when  six  months  old,  than  when  freshly 
ground. 

291.  Attempts  have  been  made  to  economize  the  power 
necessary  to  produce  a  very  high  degree  of  pulverization,  by 
passing  the  ground  cement  through  fine  wire  bolts.    It  was 

found,   however,   that   these  bolts  required 

Bolting  cement.  i        i  . 

such  irequent  renewal,  as  to  render  their  use 
in  every  way  inexpedient. 

292.  The  color  of  the  manufactured  cement,  being  due  prin- 
cipally to  the  presence  of  a  small  quantity  of  oxide  of  iron,  and 
sometimes  of  manganese,  or  to  the  carbonates  of  these  oxides, 
which,  for  all  practical  purposes,  are  conceded  to  be  a  passive 
ingredient  in  hydraulic  mortar,  should  be  a  matter  of  indiffer- 
ence to  consumers,  except  in  special  cases,  as  in  exterior  stucco 
work  or  ornamentation,  in  pavements,  and  in  the  fronts  of  edi- 
fices, when  a  particular  shade  of  color  is  sought  for.  In  fact, 
the  presence  of  a  large  proportion  of  the  coloring  principle,  like 
that  of  any  other  inert  substance,  might  be  expected  to  have  a 

tendency  to  deteriorate  the  quality  of  the  mor- 
Color  of  cement.  ,*,...,.  ,  . 

tar,  by  dimmishmg  the  cohesive  strength  of 

the  cementing  substance,  and,  therefore,  if  taken  into  con- 
sideration at  all,  ought,  at  least,  to  direct  suspicion  to  the 
darker  varieties.  On  the  contrary,  there  exists  among  dealers 
generally,  a  strong  prejudice  in  their  favor,  which,  if  ana- 
lyzed and  traced  to  its  source,  will  be  found  to  have  had  its 
origin,  not  in  opinions  based  upon  experiment,  or  even  upon 
a  theoretical  examination  of  the  substances,  but  in  the  per- 
nicious system  of  building  by  contract,  so  extensively,  and 
it  might  almost  be  said,  so  exclusively  practised  in  this  country, 


HYDKAULIC  CEMENTS,  AND  MOETARS.  163 


and  under  which  nine-tenths,  and  perhaps  nineteen-twentieths 
of  our  masonry  work,  is  superintended  by  men  whose  utmost 
endeavors  are  directed  to  "  economy  of  construction."  They, 
therefore,  encourage  and  cater  to  a  popular  belief  of  their  own 
creation,  that  a  dark  colored  mortar  is  necessarily  a  rich  and 
energetic  one,  and  give  the  preference  to  those  cements  which 
will  sustain  a  large  dose  of  sand,  without  presenting  the  ap- 
pearance of  having  been  injuriously  diluted  with  it.  The  fact 
that  some  of  the  cements  first  discovered  and  manufactured  in 
this  country  on  the  line  of  the  Erie  Canal,  and  in  Connecticut 
Yalley,  which  were  little  more  than  eminently  hydraulic  limes, 
were  light  in  color,  while  the  excellent  Parker's  Koman  ce- 
ment, which  appeared  here  soon  after,  was  very  dark-colored, 
renders  it  more  difiicult  to  abate  this  prejudice.  'No  import- 
ance whatever  is  accorded  to  the  fact,  that  the  quickest  setting 
cements  manufactured  at  the  present  day  happen  to  be  light- 
colored,  and  that  the  Portland  cements,  both  natural  and  arti- 
ficial, though  rather  slow-setting,  have  never  been  surpassed  in 
strength  and  hardness  by  any  of  the  natural  cements  of  this 
country  or  Europe. 

293.  As  to  the  oxide  of  manganese,  the  idea,  at  first  promul- 
gated by  the  chemist,  Bergmann,  and  subse- 
quently endorsed  by  Guy  ton  de  Morveau,  that    ^^^^  of  manga- 
the  hydraulic  property  was  due  to  the  presence 

of  a  few  hundredths  of  that  substance,  has  long  since  been 
abandoned,  for  the  obvious  reason  that  some  of  the  best  ce- 
ments known  are  entirely  devoid  of  it. 

294.  The  extent  to  which  the  oxide  of  iron  exerts  its  influ- 
ence, if  at  all,  upon  the  induration  of  hydraulic  mortars,  is  still 

a  subiect  of  controversy,  as  well  as  the  ques- 

,     ,        ,       .  \  .      IP.-,  Oxide  of  iron. 

tion  whether  the  virtues  claimed  lor  it  by  some 
writers,  rest  with  the  uncombined  peroxide  or  protoxide,  or 
with  a  carbonate  of  one  of  these  bases.    The  fact,  however, 
appears  to  be  well  established  that  their  presence  does  not  con- 
fer hydi'aulic  activity,  whatever  may  be  their  action  at  some 


164 


PRACTICAL  TREATISE  Ol^  LIMES, 


subsequent  stage  of  the  induration.  We  also  know  that,  al- 
though some  of  the  best  cements  known,  as,  for  instance,  the 
cement  of  Yassy,  in  France,  and  Parker's  Roman  cement,  con- 
tain a  comparatively  large  amount *of  the  carbonate  of  the 
protoxide  of  this  metal,  the  former  .Uto?  and  the  latter  .06, 
there  are  many  good  cements  in  the  United  States  which  con- 
tain less  than  .02,  while  there  are  some  meagre,  non-hydraulic 
limes,  which  contain,  after  calcination,  as  much  as  .10  of  the 
protoxide.  It  has  been  suggested  by  Messrs.  Malaguti  &  Du- 
rocher,  in  a  paper  submitted  to  the  Academy  of  Sciences  in 
July,  1854,  that  the  presence  of  the  peroxide  in  hydraulic  mor- 
tars exposed  to  the  action  of  sea-water  was  beneficial.  The  fol- 
lowing conclusions  to  which  their  experiments  led  them  are 
very  general,  and  were  to  be  considered  at  the  time  as  simply 
initiatory  to  a  more  extensive  examination. 

1st.  Those  cements  which  are  reported  as  the  best  for  "  re- 
sisting the  destructive  action  of  sea- water,  always  contain  a 
notable  quantity  of  peroxide  of  iron." 

2d.  Certain  combinations  of  silica,  alumina,  and  lime  "  give, 
under  otherwise  similar  conditions,  very  different  reactions, 
according  as  they  are  deficient  in,  or  contain  large  quantities 
of  oxide  of  iron." 

295.  M.  Yicat  throws  the  weight  of  his  high  authority 

against  the  inference  to  be  drawn  from  these  two  propositions, 

and  arrays  a  number  of  "well  ascertained  facts  in  direct  oppo- 

iiition  to  that  method  of  explaining  the  resistance  to  the 

effects  of  sea-water,"  in  the  form  of  tabular  statements,  ex- 

hibitinei:  the  amount  of  peroxide  of  iron  in  sev- 
Oxide  of  iron.  .  ,     .      t  -.. 

eral  hydraulic  limes,  cements,  &c.,  possessing 

in  different  degrees  the  power  of  withstanding  these  destruc- 
tive influences.  He  also  in  effect  reaffirms  the  opinion  ex- 
pressed by  him  as  early  as  1846,  and  subsequently  in  1860, 
that  peroxide  of  iron  exerts  an  injurious  influence  upon  hy- 
draulic materials.  He  shows  that  of  two  cements,  both  i7ide- 
st/rucUhle  by  sea- water,  one  (Medina)  contains  .12,  and  the  other 


HYDEAULIC  CEMENTS,  AND  MORTARS. 


165 


(Cahors)  .055  of  the  peroxide  of  iron.  Of  cements  slightly  de- 
structible, the  Pouilly  contains  .051  ;  the  Yassy,  .0735  ;  and 
the  Portland,  .053.  Of  cements  entirely  destructible  in  a  few 
days'  immersion,  that  from  Gutaery  (Lower  Pyrenees)  contains 
.059.  Among  the  natural  pozzuolanas,  some  from  Pome,  that 
stand  the  action  of  sea-water  well,  contain  .12  of  this  peroxide ; 
others  from  JN'aples,  that  are  unsatisfactory  under  similar  cir- 
cumstances, contain  .163  ;  those  from  the  Isle  of  Bourbon,  still 
worse,  contain  .35 ;  while  all  the  pozzuolanas  from  the  volca- 
noes of  the  Yivarais,  which  are  worthless,  contain,  on  an  aver- 
age, .20. 

296.  M.  Yicat  further  states  that  all  artificial  pozzuolanas 
prepared  with  white  clay,  and  carefully  applied,  resist  the 
action  of  sea- water. ^    Some  of  them  do  not  contain  any  iron 
at  all,  and  most  of  them  not  more  than  .012  to  .02,  while  the 
celebrated  lime  of  Theil,  hitherto  regarded  as  the  only  one 
known  that  could,  with  sand  alone,  furnish  a  mortar  indestruc- 
tible by  sea-water,  contains  but  a  trifling  quantity  of  peroxide 
of  iron,  and  sometimes  none  at  all,  while  some  other  limes, 
most  successful  in  fresh  water,  and  containing  as  much  as  .9 
or  .10  of  peroxide  of  iron,  are  destroyed  in  salt  water  after  a 
few  days.    Tlie  conclusion  drawn  by  M.  Yicat  is  that  "  it  is 
difiicult  to  attribute  a  useful  influence  to  the  peroxide  of  iron," 
in  virtue  of  the  trials  made  by  MM.  Malaguti  &  Durocher. 
It  is  submitted  that  some  doubts  may,  with  reason,  be  enter- 
tained with  regard  to  the  correctness  of  the 
premises  assumed  by  M.  Yicat,  viz.,  that  if    ^^^^  vSit'sTTn 
this  oxide  exercises  the  influence  suggested  by    ion  the  subject  of 
those  gentlemen,  in  augmenting  the  power  of 
hydraulic  mortars  to  withstand  the  dissolving  action  of  sea- 
water,  the  extent  of  this  influence  should  be  invariably  in  pro- 

*  In  view  of  the  suspicions  that  have  recently  arisen  in  reference  to  the  stability 
of  maritime  structures  laid  up  in  artificial  hydraulic  mortars,  entertained  by  some  of 
the  ablest  European  engineers,  and  men  of  high  attainments  in  practical  science, 
we  must  be  allowed  to  express  some  doubts  as  to  the  correctness  of  this  premisa. 


166 


PEACTICAL  TREATISE  ON  LIMES, 


portion  to  the  quantity  of  the  oxide  present.    May  not  the 
molecular  state  of  the  oxide,  and  the  obscure 
kcu'iarcondftiST'  variable    modifications    and  reactions 

and  heat  on  the     which  it,  like  some  of  the  other  constituent  ele- 

oxide. 

ments  of  hydraulic  mortars,  may  undergo 
during  the  calcination, — conditions  which  are  known  to  vary 
materially  with  the  duration  of  the  calcination,  and  the  degree 
of  heat  under  which  it  is  effected, — have  an  important  bearing 
upon  this  question  ?    May  not  a  portion  of  this  oxide  exist  in 

a  condition  favorable  to  its  entering  into  stable 
^tiir  and  indestructible  combinations,  while  another 

portion  is  practically  inert  or  even  injurious  in 
its  tendency,  as  is  not  unfrequently,  and  perhaps  generally  the 
case,  with  the  silica  and  the  lime  ?  Finally,  may  not  the  iron 
be  present  in  several  forms,  such  as  the  protoxide  FeO,  the  per- 
oxide FcsOs,  the  magnetic  oxide  Fe304  or  perhaps  (FeO  + 
FesOs)  ?    This  last  compound,  in  the  form  of  cinders  or  scales 

thrown  off  under  the  smith's  hammer,  has  long 

Forge  scales. 

been  known  to  possess  the  property  oi  pozzuo- 
lana,  of  conferring  moderate  hydraulic  energy  upon  common 
fat  lime,  and  although  the  activity  of  cements  cannot  in  any 
degree  be  ascribed  to  its  presence  since  some  of  the  most  active 
contain,  of  all  the  compounds  of  iron  together,  only  a  minute 
proportion ;  still  it  is  not  improbable  that  ferruginous  combina- 
tions may  be  developed,  which  are  well  adapted  to  resist  the 
dissolving  power  of  sea-water. 

297.  The  gradual  and  progressive  effects  of  sea-water  upon 

hydraulic  mortars  immersed  in  it,  notwithstand- 
Effect  of  sea-  .  .  ,  ,  ' 

water  on  mortars  ing  the  attention  which  the  subject  has  received 
not  understood.        /?        -r^  •  •     .  -n  i        i  • 

irom  iLuropean  engmeers,  is  still  enveloped  m 

considerable  doubt.    It  is  an  easy  matter  to  ascertain  that  its 

retarding  influence  upon  the  initial  hydraulic  induration  is  not 

very  great,  if  the  cement  be  mixed  up  with  fresh  water ;  and  it 

does  not  become  very  marked  when  the  cement  is  both  mixed 

with,  as  well  as  immersed  in  sea-water.    The  strength  of  mor- 


HYDEAULIC  CEMENTS,  AJS^D  MOKTAES.  167 


tars,  however,  is  considerably  impaired  by  using 
sea- water  for  mixing  them,  as  is  shown  bj  the 
following  table : 


Mixing  mortars 
with  sea-wafcer 


TABLE  IX. 

Sliowing  the  ultimate  strength  of  rectangular  parallelopipeds 
of  mortar  2"x2"x8"  formed  in  vertical  moulds,  under  a  pres- 
sure of  thirty-two  pounds  per  square  inch,  applied  at  the  upper 
end,  until  the  mortar  had  "  s&t^''  and  broken  on  supports  four 
inches  apart  by  a  pressure  from  above  midway  between  the 
points  of  support.  The  mortars  were  kept  in  a  damp  place  for 
twenty-four  hours,  and  then  immersed  and  kept  in  sea-water. 
Some  of  the  mortars  were  mixed  with  fresh  water  and  some  with 
sea-water.  The  cement  was  calcined  in  the  Flame  Kiln,  and 
the  mortars  were  ninety-five  days  old. 


Composition  of  the  mortar. 


AS, 


Pure  cement  mixed  with  fresh  water  to  a  stiff  paste  

tl  u  u  « 

"  «         n  »   

II  (I         (I  (( 

k(  (I         ((  (( 

U  U  ((  (( 

Pure  cement  mixed  with  sea-water  to  a  stiff  paste  

II  (I  (I  v. 

V.  ((  (( 

»  U  II  (I 

(I  U  (I 

II  II  II  II 

Cement  powder,  vol.  1,  sand,  vol.  2,  mixed  with  fresh  water  

U  It  II  II  II 

II  it  II  II  It 

It  (I  II  II  It 

II  II  (I  II  II 

Cement  powder,  vol.  1,  sand,  vol.  2,  mixed  with  sea-water  

It  it  II  It  It 

II  it  it  II  It 

Cement  powder,  vol.  1,  sand,  vol.  2,  mixed  with  sea-water  concentrated  by 
heat  25  per  cent  


197. 

165 
165 


goa 


>A 


499^  lbs. 


379i  " 


3132 


195 


165 


298.  Preservation  of  Cement. — Hydraulic  cement  exposed 


168 


PEACTICAL  TKEATISE  ON  LIMES, 


to  the  air  absorbs  moisture  and  carbonic  acid  gas,  and  is 
rapidly  deteriorated  bj  the  progressive  forma- 
?!^!t  ^i"*""''"      tion  of  the  carbonate  and  hydro-silicates  and 

rates  m  air.  «/ 

aluminates  of  lime,  in  the  condition  of  pow- 
der. Even  when  put  up  in  the  usual  way  in  the  casks  ordi- 
narily supplied  for  that  purpose,  which  are  quite  as  tight  as 
flour  barrels,  and  are  always  lined  throughout  with  paper,  it 
loses  much  of  its  energy  in  the  course  of  six  or  eight  months, 
and  at  the  end  of  fourteen  or  sixteen  months  is  unfit  for  use  in 
important  works,  and  is  incapable  of  sustaining  the  full  dose 

of  sand.  Cements  thus  deteriorated  are  scarcely 
d'eterioSJ!?      equal,  in  hydraulic  energy,  and  in  the  strength 

and  hardness  of  the  mortars  made  from  them, 
to  those  that  have  been  once  mixed  into  mortar,  and  repulver- 
ized  at  the  expiration  of  three  or  four  days. 

299.  When  liable  to  be  kept  on  hand  for  several  months 

cement  should  be  stored  in  a  tight  building, 

Preservation  of  f^Q^  from  any  o:reat  draught  of  air  throu2:h  it. 
cement.  ^   o  o  o 

If  the  floor  is  of  earth,  or  paved  with  stone, 
and  consequently  likely  to  condense  moisture  from  the  atmos- 
phere, the  casks  should  be  raised  several  inches 
Kps^'^*"^^^  above  it.  Unground  cement  in  the  state  of 
lumps  as  it  leaves  the  kiln,  may  be  kept  for 
two  or  three  years  without  sensible  deterioration.  Circum- 
stances might  arise  when  it  would  be  expedient  to  pursue  this 
course.  In  such  a  case  a  run  of  small  millstones  driven  by 
horse-power,  or  some  other  suitable  apparatus  for  pulverizing 
it  as  required  for  use,  would  have  to  be  provided. 

300.  Cements  that  contain  meagre  lime  in  excess,  and  bor- 

der  on  the  intermediate  limes,  are  improved  by 
Intermediate  limes  ,    ^  ...  . 

improved  by  age    age  to  within  certain  limits.    After  the  lime 

to  a  certain  time.     r.      ^    j  .      t  i  i  n  i 

has  had  time  to  slake,  or  has  so  far  progressed 
in  that  operation  that  the  process  of  mixing  up  with  water 
will  com23lete  it,  the  deterioration  commences  and  goes  rapidly 
on.    The  slaking  of  the  lime  being  due  to  absorption  of  mois- 


HYDRAULIC  CEMENTS,  AND  MOETAESL 


169 


ture,  the  cement  itself  receives  injury  from  the  same  cause, 
and  is  degraded  in  hydraulicity.  Several  of  tlie  layers  of  tlie 
deposit  in  Ulster  Co.,  'N.  Y.,  furnish  cements  of  this  type. 

301.  Genuine  cements  that  have  been  iniured  _ 

Dotonorated 

by  age  or  exposure,  or  have  from  any  cause    cements  restored 

,  ,  ,  i.      J  •        •  •     1     by  recalcination. 

become  wet,  may  be  restored  to  their  original 
energy  by  re-calcination.    For  this  purpose  it  is  convenient  to 
mix  the  cement  into  paste,  with  about  ten  per  cent,  of  clay,  to 
secure  cohesion,  and  then  form  it  into  balls  or  cakes  of  suitable 
size  for  burning.    It  is  advantageous  to  mix  the  clay,  with  the 
water  as  the  first  step,  as  its  thorough  incorporation  with  the 
cement  is  more  readily  secured  thereby.    Cement  that  has 
become  wet  through  in  the  barrels,  and  taken  a  "  set,"  as  might 
frequently  occur  on  long  sea  voyages,  may  be  broken  into 
lumps,  reburnt  in  that  condition,  and  subsequently  pulverized. 
A  bright  red  heat  of  one  and  a  half  to  two 
hours' duration  is  quite  sufficient  to  restore  the  Jequked^ 
activity  of  injured  cements. 

302.  Some  mortars  made  from  the  "  Hoffman"  brand  (para- 
graph  60),  composed   of    two  measures  of  ^  „ 

"  ^'  ^  Old  mortar  from 

cement  paste  and  one  measure  of  sand,  taken  Hoffman's  Rosen- 
in  the  summer  of  1859  from  the  Embrasure 
Target  erected  at  West  Point  five  years  previously,  was  pul- 
verized in  a  mortar  and  heated  in  a  crucible  for  one  and  a  half 
hours  at  a  bright  red  heat.  It  was  then  mixed  into  mortar 
and  formed  into  two  cakes.  One  of  these,  left  in  the  air,  bore 
the  inch  testing  wire,  loaded  to  i  pound,  in  ten  minutes,  and 
being  then  immersed,  bore  the  2V  inch  wire  and  one  pound 
weight  in  fifteen  minutes  more  ;  the  other,  immersed  as  soon  as 
mixed,  sustained  the  heavy  wire  in  fifty-five  minutes,  though 
not  very  well. 

303.  Two  varieties  of  cement,  viz. :  the  "  Hoffman"  and  the 
James  River  brands,  were  formed  into  a  paste    -r.    ,    .  ^ 

'  ^  Repulverized 

with  fresh  water  without  sand  and  allowed  to  cement  after  two 
harden  for  three  days.    They  were  then  repul-  setting. 


170 


PEACTICAL  TEEATISE  ON  LIMES, 


veiized  and  sample-cakes  of  stiff  paste  formed.  ISTeither  of 
them  would  sustain  immersion  in  water  at  all,  but  appeared 
entirely  deprived  of  hydraulicity.  The  sample  left  in  the  air 
bore  the  light  testing  wire  in  about  four  hours,  but  they 
appeared  to  have  hardened  more  from  the  effects  of  desiccation 
than  hydraulic  energy,  and  fell  to  pieces  soon  after  immersion 
in  water.  Samples  restored  by  a  red  heat  of  one  hour's  dura- 
tion, were  in  every  respect  as  energetic  as  new  cements. 
Numerous  trials  seemed  to  indicate  that  cements  repulverized 
after  but  twenty-four  hours'  induration,  are  scarcely  more  ener- 
getic than  those  that  remained     set"  three  days. 

304.  The  alkaline  silicates  were  thoroughly  tried,  as  a  means 
of  restoring  the  energy  of  damaged  cements,  but  without  suc- 
cess. The  trials  of  strength  were  confined  mostly  to  prisms 
left  in  the  air  to  harden.  The  silicate  seemed  to  operate  inju- 
riously. 

305.  Some  of  this  cement  mortar,  containing  no  sand,  repul- 

verized after  three  days'  "  settins:,"  and  without 

Its  Btren^h.  -,      .       -.  i  t     i        .  .  -. 

havmg  been  restored  by  burning,  was  mixed 
with  an  equal  volume  of  sand,  and  formed  into  prisms.  Other 
prisms  of  like  composition  were  made  of  the  same  kinds  of 
cement,  fresh  from  the  barrel.  The  breaking  weights  of  both 
are  given  in  the  following  table. 

Table  X.  shows  the  ultimate  strength  of  rectangular  prisms 
2"  X  2"  X  8"  of  mortar  formed  in  vertical  moulds,  under  a 
pressure  of  thirty-two  pounds  per  square  inch,  applied  to  the 
upper  end,  until  the  mortar  had  "  set,"  and  broken  on  supports 
four  inches  apart,  by  pressure  midway  between  the  supports. 
The  prisms  were  kept  in  sea-water  after  the  first  twenty-four 
hours,  and  were  320  days  old  when  broken.  The  cement  was 
measured  in  powder. 


HYDRAULIC  CEMENTS,  AND  MOKTAKS. 


171 


TABLE  X. 


Kind  of  ce- 
ment. 


Hoffman. 


Cement  repulverized  after  3  days'  set,  vol.  1,  sand  vol.  1 . 


James  River. 


Composition  of  the  mortar. 


Cement  fresh  from  barrel,  vol.  1,  sand  vol.  1 . 


Cement  fresh  from  barrel,  vol.  1,  sand  vol.  1 


Cement  repulverized  after  3  days'  set,  vol.  1,  sand  vol.  1 , 


Penetration 
of  point  by^ 


.065 
.072 
.075 
.095 
.075 
.090 
.077 
.100 
.050 
.057 
.045 
.057 
.097 
.112 
.102 
.112 
.080 
.085 
.097 
.100 

.077 


.113 
.117 
.125 
.112 
.122 
.127 
.160 
.137 
.159 
.132 
.165 
.077 
.092 
.085 
.092 
.165 
.187 
.177 
.187 
.130 
.147 
.145 
.160 

.135 


St:  2 


866 
822 
806 
643 
697 
228 
254 
248 
244 
217 
228 
681 
623 
585 
635 
209 
204 
271 
244 
267 
296 
279 
254 


306.  Some  of  the  James  River  cement,  manufactured  at  a 
different  time,  and  apparently  not  as  good  as  that  referred  to 
ill  the  foregoing  table,  was  obtained.  A  few  prisms  were 
made  of  this  cement  without  sand,  and  while  quite  fresh. 
The  barrel  was  then  reheaded,  and  kept  for  one  year  without  be- 
ing disturbed,  when  other  prisms  were  made,  also  without  sand. 

Both  sets  of  prisms  were  kept  in  water  for 

,   ,       ,     ,  n       •  Strength  of  dete- 

320  days,  and  then  broken  on  supports  lour  inches  riorated  James 
apart,  as  usual,  with  the  following  results  :  River  cement. 

The  prisms  formed  of  the  fresh  cement,  bore  as  an  average  of  6  trials,  402  lbs. 

"     stale       "        "  "  6     "       244  lbs. 

This  cement  being  originally  of  inferior  quality,  in  conse- 
quence probably  of  careless  burning,  as  well  as  of  a  careless  se- 
lection of  stone,  the  ratio  of  deterioration  is  doubtless  much  less 
marked  than  would  have  been  exhibited  by  a  prime  article. 

307.  Hydraulic  lime  also  loses  its  energy  by    Hydraulic  lime 

deteriorates  by 

exposure,  in  the  same  way  as  cement.  age. 
General  Treussart  tried  some  of  the  Obernai  and  Metz  hydrau- 


172 


PRACTICAL  TEEATLSE  ON  LIMES, 


lie  limes.  The  composition  of  the  raw  Obernai  Qbernai  and  Metz 
stone  was  lime,  .422;  magnesia  and  iron,  .050;  hydraulic  lime, 
silex,  .105  :  alumina,  .043;  carbonic  acid  and  water,  .380.  The 
Metz  lime  bm^nt  contains  .683  of  lime,  .090  of  magnesia,  .170 
of  clay,  and  .057  of  oxide  of  iron.  These  limes  were  slaked 
by  an  infusion  of  about  }  of  their  volmne  of  water.  Some  of 
the  lime  was  made  into  mortar,  and  formed  into  prisms,  as 
soon  as  it  was  slaked,  and  while  perfectly  fresh.  Other  prisms 
were  formed  after  the  slaked  lime  had  been  kept  for  some 
time  in  an  uncovered  vessel.  The  ages  selected  for  the  lime 
powder  were  15,  25,  30,  45,  60,  90,  and  120  days,  respectively, 
The  prisms  were  retained  12  hours  in  the  air,  and  were  then 
immersed  and  kept  in  water.  They  were  broken  on  supports  4 
inches  apart,  when  one  year  old.    The  results  are  given  below  : 

TABLE  XI. 

SHOWING  THE  STRENGTH  OF  MORTARS  1  YEAR  OLD,  IN  PRISMS  2"  X  2"  X  6",  BROKEN 
ON  SUPPORTS  4  IN.  APART,  BY  A  PRESSURE  AT  THE  MIDDLE  POINT. 


Composition  of  the  mortar. 


j  Obernai  lime  in  powder  vol. 

/  Sand  vol. 

Lime  and  sand  same  as  above  

Lime  as  above  vol. 

Sand  vol. 

Trass  vol. 

Liiiie,  sand,  and  trass  as  above  

\  Metz  lime  in  powder  vol. 

I  Sand  vol. 

[  Lime  as  above   vol. 

<  Sand  vol. 

I  Trass  vol. 


ii 


Bi-eaking  weight  of  the  mortars,  in  pounds.  The  ago 
of  the  slaked  lime  when  made  into  mortar,  is  given 
at  the  heads  of  the  column. 


264 
121 

473 

209 
116 

180*  ! 


121 

132 


7T 


299 


44 
312 


M  o 

^  a 


77 


304 


a  I 


117 

299 

352 
22 

319 


s  a 


70 


317 


66 


495 
22 

385 


Remarks  on  the  above  Table. — We  judge  from  the  results 
given  in  Table  XI.  that  hydraulic  limes  deterio- 
draulic  limes  and    rate  by  the  absorption  of  moisture  and  carbonic 
acid  gas,  if  left  exposed  to  the  air  after  slaking ; 

*  This  sample  was  found  split  longitudinally.  The  two  halves  were  carefully 
put  together,  and  the  prism  broken  in  that  way.  The  strength  must  have  been 
diminished  by  the  sphtting. 


HYDRAULIC  CEMENTS,  AJ^D  MORTAES. 


173 


but  that  the  evils  of  such  exposure  may  be  counterbalanced 
by  mixing  the  deteriorated  limes  with  a  suitable  proportion  of 
trass.  This  conclusion  might  have  been  arrived  at  from  our 
knowledge  that  trass  and  common  lime  make  a  good  mortar, 
and  that  the  practical  effect  on  hydraulic  limes,  of  exposure  to 
the  air,  is  to  reduce  them  to  the  condition  of  common  lime. 

308.  General  Treussart  also  found  by  experiment  that  the 
strenp^th  of  hydraulic  limes  is  injured  by  air-    ^  ,  ,. 

°  J  ./  Hydraulic  limes 

slaking,  in  a  ratio  varying  directly  with  their    injured  by  alr- 
hydraulicity,  but  that  mortars  composed  of  one  ^^^^"^S- 
measure  of  powdered  air-slaked  lime,  one  measure  of  sand,  and 
one  of  trass  gave  very  good  results. 


174 


PEACTICAL  TREATISE  ON  LIMES, 


CHAPTEE  YI. 

309.  Calcareous  mortae,  being  composed  of  one  or  more  of 

the  varieties  of  lime  or  cement,  natural  or  arti- 
Caloareous  mor-  ^(.lal,  mixed  with  sand,  will  vary  in  its  proper- 
ties with  the  quality  of  the  lime  or  cement 
used,  the  nature  and  quantity  of  sand,  and  the  method  of 
manipulation.  ISTo  fixed  rules  for  its  preparation,  that  shall 
be  equally  well  adapted  to  all  the  varying  circumstances 
of  locality,  temperature,  and  the  seasons,  can  be  prescribed. 

310.  The  objects  to  be  attained  by  the  use  of  mortar  are 
chiefly  of  two  kinds,  as  follows : 

First,  to  bind  together  the  solid  materials 
Their  uses.  -Qged  in  masonry  constructions  ;  or,  in  other 

words,  to  produce  in  each  particular  case,  arti- 
ficial monoliths,  of  the  required  form  and  dimensions. 

Second,  to  form  coverings  to  the  solid  materials,  under  the 
general  denomination  of  stucco  work.  Under  this  head  may 
be  included  all  exterior  covering,  and  interior  plaster  work 
and  ornamentation. 

311.  Sand  exercises  no  sensible  chemical  action  in  the  com- 

position and  induration  of  mortars  of  hydraulic 
l^^t''''  li^e  ;  if  the  sand  be  silicious,  there  is  believed 

to  ensue  a  slow  formation  of  silicate  of  lime, 
which  considerably  augments  their  power  of  resistance,  and  in 
positions  excluded  from  contact  with  the  air,  such  as  the  in- 
terior of  thick  walls,  becomes  an  important  auxiliary  in  the 
hardening  process. 


HYDEAULIC  CEMENTS,  AND  MORTARS.  175 


In  a  general  sense,  therefore,  an 3^  mixture  of  fragmentary 
substances,  like  sand,  gravel,  pebbles,  or  pieces  of  brick 
or  stone,  formed  into  a  state  of  aggregation  by  a  calcare- 
ous cementing  matter  or  matrix,  might  be  termed  mortar; 
but  as  this  definition  would  evidently  include  concrete  or 
beton,  which  is  made  by  incorporating  into  ^^^^^^.^^^ 

mortar,  fragments  of  brick  or  of  stone,  shells    cation  of  the  term 

.      ,  mortar, 
and  pebbles,  it  is  perhaps  well  to  retain  the 

technical  signification  of  the  term  mortar,  by  limiting  its  appli- 
cation to  mixtures  of  sand  and  a  paste  of  the  cementing  sub* 
stances,  reserving  for  a  general  classification  of 
mortars  and  concrete  under  one  head,  the  more  Aggregates, 
comprehensive  denomination  of  aggregates. 

312.  The  practical  strength  of  aggi-egates,  considered  with 
regard  to  their  tenacity,  hardness,  and  power  of  resisting  com- 
pression, depends  upon  four  essentially  distinct  conditions : 

1st.  The  constant  resistance  of  the  parts  enveloped  by  the 
matrix,  whether  composed  of  sand,  gravel,  peb- 
bles, fragments  of  brick  or  stone,  or  a  mixture  gregates. 
of  them  all. 

2d.  The  resistance  varying,  and  generally  increasing  with 
time,  of  the  matrix  or  cementing  matter. 

3d.  The  force  of  adhesion  between  the  matrix  and  the  other 
parts,  resulting  in  part,  from  the  former  penetrating  the  in- 
terstices of  the  latter,  and  in  part  from  the  chemical  afiinities 
existing  between  them. 

4th.  The  strength  due  to  the  interlacement  of  the  enveloped 
parts  with  each  other,  which  produces  leverage  and  friction 
among  them,  and  enlarges  the  surface  of  least  resistance. 

313.  It  might  be  inferred  theoretically,  that  the  capacity  of 
an  aggregate  possessing  no  voids,  to  resist  any  particular  kind 
of  strain,  cannot  surpass  that  of  its  matrix  or  gang ;  or  rather 
cannot  be  equal  to  it,  except  when  the  inherent  strength  of  the 
enveloped  parts,  as  well  as  the  adhesion  between  them  and 
the  matrix,  equals  or  exceeds  the  resisting  power  of  the  latter. 


176 


PRACTICAL  TREATISE  ON  LIMES, 


In  practice,  when  these  conditions  do  approximately  obtain 
in  exceptional  cases,  mortars  are  weakened  by 
we^ened^  by  the    ^^^^  addition  of  sand  or  any  of  the  substances 
sand  used.  above  mentioned.    These  latter  have  the  im- 

portant effect,  however,  of  preventing  or  dim  in- 
cises of  the  sand,  jgj^j^g  shrinkage,  of  hastening  the  induration 
of  rich  limes,  and  of  rendering  all  kinds  of  mortars  less  liable 
to  crack  in  drying,  which  is  often  of  very  great  advantage. 
They  are,  moreover,  by  far  the  least  costly  ingredient  of  mor- 
tars, and  a  due  regard  to  economy  compels  their  use  in  the 
largest  possible  proportions. 

314.  It  might  also  be  inferred  that  the  minimum  amount  of 
.  ,    .  .     the  cementinoi:  material  that  can  be  used  in  any 

Theoretical  mmi-  ^  °  ^ 

mum  of  cement-  case,  is  exactly  equal  to  the  volume  of  the  voids 
mg  su  s  anoes.  ^j^^  sand,  w^hen  the  latter  is  well  compacted. 

This  theory  supposes  that  there  is  no  shrinkage  in  the  matrix 
w^hile  hardening,  and  that  the  manipulation  is  complete.  But 
as  these  conditions  can  never  be  fully  attained  in  practice,  it  is 
unsafe  to  descend  to  this  inferior  limit.  Moreover,  mortars  com- 
Not  safely  appli-  P^^^^  ^^^^^  principle  would  be  deficient  in 
cable  in  practice,  both  adhesive  and  cohesive  power,  from  the 
fact  that  the  particles  of  sand  would  present  a  large  area, 
practically  void  of  matrix,  to  the  surfaces  of  the  solid  ma- 
terials that  are  to  be  bound  together,  and  would,  for  the  same 
reason,  be  in  more  or  less  intimate  contact  with  each  other 
throughout  the  mass.  In  order  to  avoid  these  defects,  it  is 
customary  to  determine  the  amount  of  cementing  matter  to  be 
used  in  any  particular  case,  by  adding  45  to  50 

Proportion  of  ,  ,  *  •  i  •  i 

sand  to  the  gang  per  cent,  to  the  volume  01  void  space  m  tlie 
of  mortars.  sand.    One  method  of  ascertaining  these  voids 

is,  to  determine  the  volume  of  water  which  a  known  volume 
To  determine  the  of  the  sand  (damp  and  well  compacted  in  a  ves- 
voids  in  the  sand,  suitable  form)  will  receive  ;  another,  ap- 

plicable only  when  all  the  particles  of  sand  are  derived  from 
the  same  kind  of  rock,  is  to  ascertain  the  weight  of  a  known 


HTDEAULIC  CEMENTS,  AND  MOETAES. 


volume  of  the  sand  and  compare  it  with  the  weight  of  an  equal 
volume  of  the  solid  rock,  as  calculated  from  its  known  specific 
gravity. 

315.  "When  sands  of  various  sizes  are  at  hand,  a  considerable 
saving  of  the  cementing  material  may  be  g^nds  of  different 
secured  by  mixing  them  together  in  suitable    sizes  can  be  mixed 

rn      1  •        1  .        •  advantageously, 

proportions.    To  determme  this  point,  take  a 

measure  of  convenient  capacity,  say  a  little  more  than  one 

cubic  foot,  and  put  in  it  a  known  volume,  say  one  cubic  foot, 

of  the  coarsest  variety  of  sand.    Then  add  to  it,  little  by  little, 

so  long  as  there  is  no  augmentation  of  volume,  the  sand  which 

stands  next  in  order  of  size,  shaking  the  vessel  well  during  the 

operation.    Add  to  this  mixture  in  the  same  way  the  other 

sands  in  regular  order,  so  long  as  there  is  no  increase  of  bulk. 

The  original  volume  of  the  coarsest  sand,  and  the  several 

v^olumes  of  the  other  varieties  successively  added  to  it,  will 

indicate  the  proportion  in  which  they  should  be  combined,  in 

order  to  produce  a  mixture  possessing  the  smallest  measure  of 

void  space  which  they  are  capable  of  yielding.    Having  made 

the  mixture,  its  voids  may  be  measured  by  either  of  the  methods 

given  above,  or  by  subtracting  from  the  known  voids  of  the 

coarsest  variety,  the  difference  between  the  aggre-  computation  of 

gate  volume  of  added  sands,  and  their  aggre-  tlie  voids  of 

mixed  sand. 

gate  voids. 

316.  The  density  of  sand  depends  somewhat  on  its  state  of 
humidity  and  the  manner  of  measuring  it.  In  determining  the 
properties  of  the  constituent  parts  of  mortars,  due  allowance 
should  always  be  made,  as  ascertained  by  trial,  for  these  causes 
of  variation.  A  convenient  method  of  ascertaining  the  pro- 
portion of  grains  of  different  sizes  in  any  given  kind  of  sand, 
with  a  view  to  institute  a  comparison  between  different  varie 
ties,  is  by  usina;  sieves  of  various  decrees  of  fine- 

'       \  ,  .  ,  ^  ,  Sifting  tbe  sand, 

ness,  noting  the  amount  by  weight  or  volume 

retained  by  each  sieve  in  succession,  commencing  with  thr 

coarsest.    These  several  amounts,  added  to  that  which  passea 

12 


178 


PKACTICAL  TREATISE  ON  LIMES, 


through  the  last  or  finest  sieve,  should  be  equal  to  the  known 
amount  taken  for  trial.    Sieves  are  classified  into  numbers, 
which  correspond  with  the  number  of  openings 

Classification  of  i  i  •        t       i  •     i     i?  ^.i        •  r 

ggj.jgg  embraced  in  a  lineal  inch  oi  the  wire  gauze  of 

which  thej  are  made.  Those  used  in  the  experi- 
ments reported  in  this  work  were  Nos.  12,  18,  24,  30,  40,  50, 
and  60.  A  few  of  the  many  sands  that  have  been  examined 
are  introduced  into  the  following  table,  which  contains  an  equal 
quantity  of  each  kind  represented  by  1.000. 


TABLE  XIL 


No.  1. 

Calcareous 
sand,  from 
Key  West, 
Fla. 

No.  2. 

Sand,  from 
Governor's 
Island,NY. 
Harbor.* 

No.  3. 

Mixed  sili- 
cious  sand. 

No.  4. 

Mortar 
sand,  Fort 
Kichmond. 

No.  5. 

Sand,  from 
Brooklyn, 
N.  Y. 

Weight  of  grains  between  ^^2" 

in.  and  -i-g-  in.  diameter, 
Weight  of  grains  between  -^^ 

in.  and  ^4-  in.  diameter, 
Weight  of  grains  between  2-4 

in.  and  in.  diameter. 
Weight  of  grains  between  -3-0 

in.  and  -^^  in.  diameter. 
Weight  of  grains  between  -^q 

in.  and  g-o  in.  diameter, 
Weight  of  grains  between  5^0- 

in.  and  -^q  in.  diameter, 
Weight  of  grains  less  than  -gV 

in.  diameter. 

Total  

.080 
.138 
.243 
.222 
.138 
.103 
.076 

.163 
.302 

,352 
.183 

.140 
.175 
.584 
.043 
.019 
.008 
.031 

.038 
.092 
.179 
.183 
.224 
.284 

.341 
.302 
.163 
.119 

.060 
.015 

1.000 

1.000 

1.000 

1.000 

1.000 

Percentage  of  void  space  by  ) 
volume.  ) 

.347 

.363 

.339 

1064  lbs. 

103|  lbs. 

107i  lbs. 

*  This  sand  is  fine  grained,  containing  a  very  snaall  proportion  of  particles  exceeding  ono 
thirtieth  of  an  inch  in  diameter,  which  is  in  the  condition  of  rather  smooth  gravel,  heterogena 
ously  distributed  throughout  the  mass. 


1  cubic  fDot  of  sand,  No.  3,  damp  and  not  compacted,  weighed  87  pounds. 
1    "       "        "       "    damp  and  compacted,  "       97  " 

1    "       "        "       "    dried  in  an  oven  and  not  comp.,"      97^  " 


HYDRAULIC  CEMENTS,  AND  MOETAES. 


179 


1  ctibic  foot  of  sand,  No.  3,  dried  and  compacted,  weighed  106^  pounds. 

1    "       *'        "  comp.  and  afterwards  dampened   *'     112^  " 

1.11^  cubic  feet  of  loose,  damp  sand  has  its  volume  diminished,  by  shaking,  to 
1  cubic  foot. 

1.09  cubic  feet  of  loose,  oven-dried  sand  has  its  volume  diminished,  by 
shaking,  to  1  cubic  foot. 


METHODS  OF  SLAKING  LIME. 

317.  Lime  is  usually  sent  to  market  in  barrels,  either  in 
lumps,  as  it  leaves  the  kiln,  or,  in  the  case  of 

those  varieties  that  are  more  or  less  meagre,  and  S^the^market^^ 
consequently  difficult  to  reduce  to  fine  pulp  by 
any  of  the  known  methods  of  slaking,  in  the  condition  of 
coarse  powder  to  which  it  has  been  brought  by  grinding.  In 
either  case,  it  must  be  slaked  before  it  can  be  employed  as  a 
matrix  for  mortar. 

318.  Three  methods  of  slaking  lime  are  usually  described  in 
works  on  mortars ;  on  the  continent  of  Eu- 
rope, the  third  method,  and  in  the  United  States,    Three  methods  of 
the  second  and  third  are  seldom  resorted  to  in  ^^^^^^ 
practice. 

319.  The  first  or  ordinary  method  termed  drowning,  from 
the  excessive  quantity  of  water  sometimes  injudiciously  em- 
ployed, consists  in  pouring  upon  the  lumps  of  lime,  collected 
together  in  a  layer  of  uniform  depth  not  exceed- 
ing six  to  eight  inches,  either  in  a  water-tight  drownkTg.^^^' 
wooden  box  or  a  basin  formed  of  the  sand  to  be 
subsequently  added  in  making  mortar,  and  coated  over  on  the 
inside  with  lime-paste,  to  render  it  impervious  to  water,  a  suf- 
ficient measure  of  fresh  water, — previously  ascer- 
tained approximately  by  trial, — to  reduce  the  ^^once.*^^ 
whole  to  the  consistency  of  thick  pulp.    It  is 

important  that  all  the  water  required  for  this  purpose,  which, 
with  the  different  limes,  will  vary  from  two  and  a  half  to  three 
times  the  volume  of  the  quicklime,  should  be  added  at  the  out- 
set, or,  at  least,  before  the  temperature  becomes  sensibly  ele- 


180 


PRACTICAL  TREATISE  ON  LIMES, 


vated.  In  this  condition  the  lime  will  remain  entirely  sib- 
merged,  and  comparatively  quiescent,  until  after  an  interval  of 
five  to  ten  minutes,  the  water  becomes  grad- 
The  slaking.  usiWj  heated  to  the  boiling  point,  when  a  sud- 
den evolution  of  vapor,  a  rapid  increase  in  volume,  and  a  reduc- 
tion of  the  lime  to  pulp,  ensues.  The  increase  of  volume  is 
sometimes  denominated  the  "  growth." 

320.  This  process  is  liable  to  great  abuse  at  the  hands  of 

workmen,  who  are  apt  to  use  either  too  much 
process^^*^'^        water,  thus  conferring  upon  the  slaked  lime  a 

condition  of  semi-fluidity,  and  thereby  injuring 
its  binding  qualities ;  or,  not  having  used  enough  in  the  first 
instance,  they  seek  to  remedy  the  error  by  adding  more  after 
the  extinction  has  well  progressed,  and  a  portion  of  the  lime  is 
already  reduced  to  powder,  thus  suddenly  depressing  the  tem- 
perature, and  chilling  the  lime,  which  renders  it  granular  and 
lumpy. 

321.  As  soon'  as  all  the  water  required  has  been  poured 
upon  the  lime,  it  is  recommended  to  cover  up  the  vessel  con- 
taining it  with  canvas  or  boards,  in  order  to  concentrate  the 
heat  and  the  escaping  vapor,  and  direct  their  action  upon  the 

uppermost  portions  deprived  of  immediate 
to  L^covered  up.    contact  with  the  water,  by  the  swelling  of  the 

portions  at  the  bottom.  When  it  is  not  practi- 
cable to  apply  this  covering,  a  tolerable  substitute  is  found  in 
Sand  may  be  sand  to  be  subsequently   added  to  the 

used  for  this         mortar.    This  can  be  spread  over  the  lime  in  a 

layer  of  uniform  thickness,  after  the  slaking  has 
well  progressed.     Another  precaution  of  equal  and  perhaps 

greater  importance  is,  not  to  stir  the  lime 
S'^eS^ft^rt.    whilst  slaking;  but  to  allow  it  gradually  to 

absorb  the  water  by  capillary  attraction  and  its 
natural  avidity  for  it,  taking  care  that  all  portions  are  supplied 
with  it  to  that  degree  requisite  to  produce  a  paste  of  the 
slaked  lime,  and  not  a  powder.    When  the  lime  is  to  be  used 


HYDEAULIO  CEMENTS,  AND  MOETARS.  181 


for  whitewashing  or  grouting,  the  water  should  be  added  at 

the  outset  in  larger  quantities  than  specified 

above,  and  the  whole  mass  should  be  run  off  wMtewashing. 

while  hot  into  tight  casks,  and  covered  up  to 

prevent  the  escape  of  water. 

322.  In  slaking,  the  essential  point  is  to  secure,  if  possible, 
the  reduction  of  all  the  lumps.    It  will  be  found  difiicult  to 
obtain  this  result  with  the  hydraulic  varieties,    Hydraulic  limes 
and  the  difficulty  increases  in  a  direct  ratio  with    slake  with  diffi- 

.  culty. 

the  hydraulic  energy,  until  we  reach  the  inter- 
mediate limes,  or  the  inferior  limit  of  cement,  when  the  reduc- 
tion must  be  effected  by  mechanical  means.    Even  with  those 
hydraulic  limes  that  do  slake,  it  is  often  necessary  to  employ  a 
mortar  mill  to  reduce  the  lumps, — a  condition    Mechanical  means 
which  should  always  be  secured,  as  these  lumps    pi^e*^°^for  rT' 
constitute  not  only  a  dangerous  substitute  for    ducing  them, 
sand,  if  left  intact,  but  furnish  when  pulverized,  the  most  ener- 
getic portion  of  the  gang. 

323.  Slaking  hy  Immersion. — The  second    second  process 

method  of  slaking  i^y  immersion).^  consists  in     of  slakmg. 

suspending  the  quicklime,  previously  broken  into  pieces  of  about 

the  size  of  a  walnut,  and  placed  in  a  basket  or  other  suitable 

contrivance,  in  water,  for  one  or  two  minutes,  taking  care  to 

withdraw  it  before  the  reduction  commences.    The  lime  should 

then  be  quickly  heaped  together,  or  emptied 

,  ,  ;  ,  -         .        ,  Precautions, 

into  casks  or  bins,  and  covered  up,  m  order  to 

concentrate  the  heat  and  prevent  the  escape  of  vapor.    In  this 

condition  it  soon  begins  to  swell  and  crack,  and  finally  becomes 

reduced  to  a  fine  powder,  which  may  be  preserved  several 

months  without  serious  deterioration,  if  packed  in  casks,  and 

kept  from  direct  contact  with  the  atmosphere.    The  expense 

which  would  ordinarily  attend  the  practical  application  of  thia 

process,  and  the  difiiculty,  and  even  impossi- 

.  .       \  .         .  .  This  process  ei- 

bility  of  securing  with  certainty,  at  the  hands  of   pensive  and  di£S- 

v\x)rkmen,  the  period  of  immersion,  have  led  to  ^^^* 


182  PEACnOAL  TREATISE  ON  LIMES, 


a  modification  of  it,  which  consists  in  sprinkling  the  broken 
A  modification  fragments  formed  into  heaps  of  suitable  size, 
of  it-  with  one-fourth  to  one-third  of  their  volume  ol 

water.  This  should  be  applied  from  the  rose  of  a  finely  gauged 
watering-pot,  after  which  the  lime  should  be  immediately  cov- 
ered with  the  sand  to  be  used  in  the  mortar.  In  this  condition 
it  should  not  be  disturbed  for  at  least  a  day  or  two,  and  the 
Practice  in  Eu-  Opinion  prevails  in  the  southern  portions  of  the 
^<^P®-  continent  of  Europe  that  the  quality  of  the  lime 

is  improved  by  allowing  the  heaps  to  remain  several  months, 
without  any  other  protection  from  the  inclemency  of  the 
weather  than  an  ordinary  shed,  open  on  the  sides.  In  the 
vicinity  of  Lyons  this  custom  very  generally  obtains,  the  au- 
tumn being  usually  selected  for  slaking  all  the  lime  required 
for  the  following  season's  operation.  In  Europe,  this  method 
of  slaking  is  applied  to  the  fat  and  slightly  hydraulic  limes 
only,  and  not  to  those  that  are  eminently  hydraulic,  upon 
which  it  seems  to  act  disadvantageously,  by  depriving  them, 
in  a  measure,  of  their  hydraulic  energy. 

324.  Spontaneous  slaking. — Quicklime  has  a  great  avidity 

for  water,  and  when  not  secured  from  direct 

Third  process —  ' 

Spontaneous  or  contact  with  the  atmosphere,  gradually  absorbs 
air  slaking.  moisture  from  it  and  falls  into  powder,  exhibit- 
ing but  very  slightly,  and  sometimes  not  at  all,  the  other  phe- 
nomena usually  developed  in  slaking.  The  lime  is  then  said  to 
be  slaked  sjpontaneously ^  or  air  slahed. 

325.  It  has  been  claimed  by  some  engineers  that  this 

method,  if  the  precaution  be  taken  to  stir  the 

Thought  to  con-      ,  ,  , 

fer  hydrauiicity  lime  Irequently,  so  as  to  expose  every  portion 
in  ashght  degree.  ^.^^^'^  ^^^^^^^^  ^.^j^  ^^^^  ^^^^^^^ 

a  slight  degree  of  hydrauiicity  upon  fat  lime ;  and  Culmann, 
_  .  .     .  ^  ,       in  his  "  Cours  sur  les  Chaux,  Mortiers,  et  Mas- 

Opinion  of  Cul-  ' 
mann  needs  tics"  says,  "  it  produces  very  advantageous  re- 

sults upon  fat  or  feebly  hydraulic  limes  that 
are  to  be  mixed  with  pozzuolana  and  used  under  water."  It 


HYDRAULIC  CEMENTS,  AND  MOETAES.  183 


is  believed  that  both  of  these  statements  need  confirmation. 
A  great  and  insurmountable  objection  to  the  process,  however- 
is  the  expense  of  storage  room  or  sheds  which  it  necessarily  . 
volves,  to  say  nothing  of  the  time  required  for 
its  completion.  Spread  out  in  layers  of  from  ten  ortSFocSs. 
to  twelve  inches  in  depth,  some  varieties  of  fat 
lime  might  become  thoroughly  reduced  in  twenty  or  twenty- 
five  days;  others  would  require  as  many  weeks;  while  with  a 
few,  the  process  would  continue  for  a  whole    Hydraulic  limes 
year.    Hydraulic  limes  are  greatly  injured  by  ^J"^^^^ 
spontaneous  slaking.    Fat  limes  slaked  to  powder  by  the  second 
or  third  process,  are  converted  into  paste  with  less  water,  and 

undergo  a  less  aup-mentation  of  their  orisrinal 

^  ^  ^  Remarks, 

volume,  than  w^hen  slaked  by  the  first  process. 

326.  By  neither  of  the  three  processes  of  slaking,  nor  any 
modification  of  them,  have  I  succeeded  in  obtaining  as  great  an 
augmentation  of  the  volume  of  fat  lime  measured  in  the  state 
of  paste,  as  is  stated  by  M.  Yicat  to  belong  to  the  fat  limes  of 
France,  viz. :  that  one  volume  of  the  quicklime  in  lumps,  by 
the  absorption  of  2.91  volumes  of  water,  will  give  3.5  volumes 
of  paste. 

According  to  the  same  authority,  these  limes  slaked  by  im. 
raersion  to  powder,  and  afterwards  reduced  to    ^  Yicat's  de- 
paste,  absorb  1.72  of  water,  giving  2.34  of  paste  ;  Auctions, 
while,  by  spontaneous  slaking  they  required  1.88  of  water, 
and  gave  2.58  of  paste.    It  is  also  stated  that  the  hydraulic 
limes  in  slaking  absorb  1.05  volumes  of  water    increase  of 
by  the  first  process,  .71  by  the  second,  and  .68  vo^^^^- 
by  the  third,  producing  respectively  1.37,  1.27,  and  1.00  vol- 
umes of  paste. 

327.  I  have  repeatedly  tried  all  the  limes  ofiered  to  any 
extent,  in  the  New  York  market.  In  slaking  them,  quantities 
of  five  to  ten  pounds  were  s^enerally  employed  ;  ^ 

^  ^  jr./?     Expermients  m 

and  the  utmost  care  was  taken,  in  all  cases,  to  slaking  American 
obtain  perfect  accuracy  in  the  weights  and  meas- 


184 


PRACTICAL  TREATISE  ON  LIMES, 


urements,  and  bj  the  use  of  glass  and  tin  vessels  to  prevent  the 
waste  or  absorption  of  water.  The  glass  vessels  found  most 
Vessels  used  convenient  were  two  cyhndrical  jars,  one  eight 
inches  in  diameter  and  eighteen  inches  deep, 
and  the  other  three  inches  in  diameter  and  ten  inches  deep. 
They  were  accurately  ground  off  at  the  bottom  to  a  plane  sur- 
face at  right  angles  to  the  axis,  so  as  to  stand  in  a  vertical 
position  on  a  horizontal  surface,  and  were  graduated  to  cubic 
inches,  and  the  small  one  to  fractions  of  an  inch  throughout  their 
entire  length.  The  large  jar  was  used  for  determining  the  vol- 
ume of  the  quicklime  and  of  the  resulting  powder  or  paste  ;  the 
small  one,  for  measuring  the  water  absorbed  in  slaking.  When 
the  quicklime  to  be  tried  was  in  the  condition  of  lumps,  the 
usual  process  of  ascertaining  its  volume  by  the  displacement  of 
sand  was  employed. 

328.  To  hold  the  lime  while  slaking,  tin  cans  about  one  foot 
square  and  one  foot  deep,  were  found  to  answer  a  good  purpose. 

329.  General  Totten,  from  an  average  of  many 
Results  of  Gen.  .  -,        -r^        a  -.  i  i  c 

Totteu's  experi-     trials  at  l*  ort  Adams,  states  that  one  volume  of 

quicklime  slaked  with  \  its  volume  of  water 
gave  an  average  of  2.27  of  powder ;  f  of  water  gave  1.74 ;  f 
gave  1.81,  while  equal  volumes  gave  2.06.  Slaked  by  drown- 
Increaseofvol-      i^g^  ^.54  volumes  of  water  gave  2.68  of  thin 

paste ;  and  by  sprinkling,  1.70  of  water  gave 
1.98  of  thin  paste.  Mixing  the  powder  with  .40  of  water  gave 
.66  of  thick  paste,  while  .50  gave  .76  of  thinner  paste.  One 
volume  of  lime  slaked  spontaneously  produced  1.84  of  powder, 
and  one  volume  of  this  powder  and  .50  of  water  gave  .75  of 
thin  paste.  One  volume  of  quicklime  when  pulverized,  gave 
,90  of  powdered  quicklime. 


330.  TABLE  XIII. 


Shows  the  results  obtained  by  many  trials  of  slaking  applied 
to  the  limes  in  common  use  in  the  United  States : 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


185 


18 


Kind  of  lime  used. 


Kocklaud  lump  lime  

J  Sing  Sing  lump  lime  from 
I     Sing  Sing  marble  

Rondout  ground  lime  

U  (I  u 

tl  «  » 

(I  it  K 

Glen's  Falls  lime  in  lumps  


by  immersion. 


"  slaked 


Before 
slaking. 


11 


91.2 
86.5 
91.2 
95.0 

87.4 

89.3 
88.4 
110.2 

well 
shaken. 

110.2 

well 
shaken. 

115.9 

well 

shaken. 
124.5 
well 

shaken. 
1^.5 
well 

shaken. 
128.3 
well 

shaken. 

93.1 
93.1 
93.1 


91.2 


87.4 


After  slaking. 

Eatio  of  increase 

to 

Volume  of  watei 
soi-bed,  in  cubi 
inches. 

o 
a, 

xi 

S  c3 
"  A 

II 

bf) 
'3 

0 

a 

235.6 
269.8 
182.4 

11.19 
11.78 
13.25 
11.06  + 

224.2 
245.1 
292.6 
227.0 

2.24 
2.36 
2.65 
2.21  + 

2.46  + 
2.83  + 
3.21- 
2.40 

210.0 

11.12 

227.0 

2.22  + 

2.61- 

197.6 
195.7 

11.78 
10.67 
10.62 

248.9 
225.1 
222.3 

2.86— 
2.13  + 
2.12  + 

2.79— 
2.56- 
2.00  + 

201.4 

11.37 

239.6 

2.27  + 

2.14 

247.0 

281.2 

2.42  + 

209.0 

11.37  + 

248.9 

2.27  + 

2.00 

209.0 

11.44- 

249.9 

2.29- 

2.00  + 

197.6 

11.25 

247.0 

2.25 

1.93- 

269.8 
267.9 
279.3 
51.2 

to  produce 
a  powder. 

181.5 
to  produce 
a  paste. 

68.4 
to  produce 
a  powder. 

201.4 
to  produce 
a  paste. 

13.33 
12.44 
13.50 
6.19 
of  powdei. 

10.50 
of  paste. 

6.62  + 

of  powder. 

10.87  + 

(.f  paste. 

285.0 
271.7 
304.0 
260.3 
of  powder. 

202.8 
of  paste. 

285.0 
of  powder. 

224.2 
of  paste. 

2.66-- 
2.49- 
2.70 
1.24 

for  powder 

2.10 
for  paste. 

3.06  + 
2.92- 
3.26  + 
2.86 
for  powder 

2.54 
for  pa«te. 

EXPLANATION  OF  THE  ABOVE  TABLE. 

No.    1.  About  one-half  the  quantity  of  water  mentioned  was  poured  on  at  once, 

and  the  balance  gradually,  with  occasional  stirring. 
No.   2.  Most  of  the  water  was  poured  on  at  the  outset,  and  the  lime  was  stirred 

occasionally. 

No.  3.  All  the  water  (269.8  cubic  inches)  was  poured  on  at  once,  submerging  the 
lime  completely,  in  which  condition  it  was  left  covered  up  for  several  hours 
without  being  agitated  at  all. 

No.  4.  83-1  cubic  inches  were  first  added,  and  the  balance  of  the  182.4  inches  grad- 
ually, with  occasional  stirring. 

No.   5.  The  water  was  poured  on  gradually,  with  occasional  stirring. 

No.  6.  The  Hme  was  nearly  covered  up  with  the  water  at  the  outset.  "When  the 
slaking  had  well  progressed,  more  was  added,  with  occasional  stirring. 

No.   7,  Water  poured  on  gradually,  with  occasional  stirring. 

No.   8.         do.  do  do.  do. 


ISG  PEAC'TICAL  TREATISE  ON  LIMES, 

No.  9.  All  the  water  was  poured  on  at  the  outset,  and  after  the  expiration  of  one 
hour,  the  Urae  was  stirred. 

No.  10.  All  the  water  was  poured  on  at  once,  and  the  canvas  was  covered  up,  and 
not  disturbed  until  the  next  day.  The  paste  was  very  thin  and  of  the  con- 
sistency of  cream. 

No.  11.  Water  all  poured  on,  and  the  can  covered  as  before.  The  paste  was  much 
stiflfer  than  No.  10,  but  rather  lesg  so  than  most  of  the  foregoing. 

No.  12.  Water  poured  on  as  above,  and  not  disturbed  until  the  following  day. 
Tho  paste  was  not  quite  so  thin  as  No.  10,  but  much  more  so  than 
No.  11. 

No.  13.  Water  all  poured  on,  and  the  can  covered  as  above.  The  paste  was  a 
trifle  less  stiff  than  that  adopted  as  the  standard  in  these  compari- 
sons. 

No,  14.  The  lime  was  broken  into  pieces  of  1  to  1|  inch  cube,  and  209  cubic 
inches  of  water  poured  on  at  once.  The  can  was  then  covered  up  with 
canvas  and  left  for  several  hours,  until  it  had  become  cool.  The  lime  was 
then  in  the  condition  of  a  powder,  requiring  QO-^  cubic  inches  of  water  to 
reduce  it  to  a  paste  of  the  requisite  consistency. 

No.  15.  The  lime  was  broken  up  as  above,  and  83^  cubic  inches  poured  over  it  at 
the  outset.  The  can  was  left  open,  and  the  balance  of  the  water  added  in 
quantities  of  20  to  24  cubic  inches  at  a  time,  until  211  cubic  inches  had 
been  used.  This  was  just  enough  to  produce  a  damp  powder  which  re- 
quired 56-^)  cubic  inches  more  to  bring  it  to  a  paste. 

No.  16.  The  lime  was  broken  up  as  in  No.  14,  and  submerged  in  270  cubic  inches 
of  water.  The  can  was  then  covered,  and  not  disturbed  until  after  the  ex- 
piration of  four  hours.  9-i%  inches  of  water  were  added  to  produce  the  re- 
quisite degree  of  consistency. 

No.  17.  The  hme,  broken  as  in  No.  14,  was  placed  in  a  basket  and  suspended  one 
minute  in  water,  of  which  it  absorbed  51-^  cubic  inches.  It  was  then  poured 
into  a  can,  covered  up,  and  not  disturbed  until  the  next  day,  when  it  was 
found  to  be  reduced  to  a  powder  containing  about  ten  per  cent,  of  smail 
lumps.  After  these  were  pulverized,  130  cubic  inches  of  water  brought 
the  whole  to  a  stiff  paste. 

No.  18.  The  lime,  broken  as  above,  was  suspended  in  water  If  minutes,  and  was 
then  poured  quickly  into  a  can,  and  kept  covered  up  until  next  day,  when 
it  was  found  very  well  slaked,  with  very  few  lumps,  and  none  but  what 
could  easily  be  rubbed  fine  under  a  spatula. 

331.  Action  of  the  hydrates  in  the  air. — A  paste  of  the  hy- 
drate of  fat  lime  in  free  contact  with  the  atmosphere,  absorbs 

carbonic  acid  gas  upon  the  surface,  although 
Sneln^the^ah-^  point  of  complete  saturation,  and 

becomes  coated  with  a  mixture  of  hydrate  and 
carbonate  of  lime,  (CaO.COg+CaO.HO).  The  gas  gradu- 
ally penetrates  the  substance,  at  a  rate  of  progress  con- 
stantly on  the  decrease,  and  at  the  end  of  one  year,  according 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


18? 


to  M.  Yicat,  the  layer  of  impure  carbonate  is 
from  .10  to  .12  of  an  inch  in  depth.    The  same  f^l'^'^^l 
authority  says,  that  the  absorption  and  penetra- 
tion of  this  gas  proceeds  more  rapidly  in  the  hydraulic  limes 
than  in  the  fat  limes — a  statement  which  not  only  needs  confir- 
mation, but  is  believed  to  be  the  converse  of  what  is  true. 
My  researches  lead  me  to  the  same  results  as  those  enunciated 
by  Geo.  Eobertson,  Esq.,  in  a  paper  recently    ^^^^^  absorp- 
read  before  the  "  Koyal  Society  of  Edinburgh,"    ^}^^  ^^^^^s  ^h® 

^  ^  '       different  limes  in- 

viz. :  "  The  depth  to  which  carhonic  acid  is  ah-    verseiy  as  their 
sorhed  into  mortar  in  a  given  time^  and^  to  ^y^^^^^^*)^- 
a  certain  extent^  the  induration  from  that  cause  varies  in- 
versely with  the  hydraulic  properties  of  the  lime,  which 
depend  upon  the  silica  contained  in  itP 

332.  The  incrustation  is  due  in  the  case  of  hydraulic  limes 
to  the  combined  influence  of  reactions,  con-  .  „ 

'  The  covering  of 

siderably  more  complicated  and  obscure  than  subcarbonate 

those    which    obtain    with    the   hydrate  of 

fat  lime.    The  hydrosilicate  and  aluminate  of  lime  (Si03  4 

CaO  +  6  HO)  and  (AlA  +  3  CaO  +  6HO)  are 

formed  in   addition   to  the  hydrocarbon  ate.    Other  compounds 

lormea. 

The  formation  of  these  compounds  of  silica  and 
alumina  is  not  confined  to  the  crust  on  the  surface,  but  takes 
place  throughout  the  mass,  and  is  really  the  principal  eflicient 
cause  of  the  induration  of  this  class  of  limes,  when  placed  under 
water,  or  in  humid  localities  excluded  from  atmospheric  influ- 
ences.    It  appears  not  improbable  that  these  circumstances 

attending  the  superficial  induration  of  hydraulic    ^.^^  ^ 

o  Difficult  to  meas- 

limes  in  the  atmosphere,  have  led  to  errors  in    ure  the  subcar- 

1      T      1         1  .         p      ^  bonate  covering. 

measuring  the  depth  oi  the  covering  oi  subcar- 
bonate, owing  to  the  difiiculty  in  determining  with  precision 
the  exact  position  of  the  surface  which  separates  the  crust 
formed  by  the  combined  influence  of  exterior  and  interior 
causes,  from  those  portions  in  which  the  induration  is  entirely 
independent  of  atmospheric  influences. 


188 


PRACTICAL  TREATISE  ON  LIMES, 


333.  The  Lardness  assumed  by  the  hydrate  in  the  air  is  in- 

timately connected  with  the  process  of  slaking, 
S^eenTardness  appears  to  sustain  a  direct  ratio  with  the 

of  hydrate  and      increase  in  volume.    The  three  modes  of  slaking 

mode  of  slaking.  ^  " 

arranged  in  order  of  their  superiority  in  this 
respect  stand  as  follows : 

1st.  For  fat  limes :  ordinary  slaking,  spontaneous  slaking, 
slaking  by  immersion. 

2d.  For  hydraulic  limes  :  ordinary  slaking,  slaking  by  immer. 
sion,  spontaneous  slaking. 

334.  The  hydrates  of  fat  lime,  drying  in  the  air,  shrink  and 
crack  to  such  an  extent,  that  they  cannot  be  employed  in  mor- 
tar for  masonrv  without  a  laro^e  dose  of  sand. 

Hydrate  of  lime  -^^^^'^^  hydrate  under  wotev. — 

soluble  in  water  The  hydrate  of  fat  lime  is  soluble  to  the  last  de- 
changed.  It  ab-  gree  in  water  frequently  renewed.  Immersed 
sorbs  water.  -^^       condition  of  stiff  paste  in  still  water,  it 

absorbs  a  certain  quantity  of  the  fluid,  without  any  augmenta- 
tion of  volume,  or  sensible  change  of  consistency.  The  amount 
thus  absorbed  depends  upon  the  mode  of  slaking.  A  paste 
formed  by  the  ordinary  oy fii^st  process  takes  up  .04  of  water; 
if  slaked  by  immersion^  nearly  .11 ;  and  if  ^3^^>-slaked,  .245. 
An  increase  in  density  ensues,  varying  with  the  amount  of 
water  absorbed,  and  we  might  therefore  be  justified  in  assum- 
ing that  fat  limes  slaked  by  the  second  or  third  process,  which 
are  to  be  rendered  hydraulic  by  the  addition  of  natural  or  arti- 
Mixed  with  poz  ^cial  pozzuolana,  or  cement,  would  be  superior 
zuoiana,  or  ce-  to  tliose  slaked  by  the  first  process,  on  account 
01  the  more  intimate  contact  between  the  ingre- 
dients, and  consequently,  the  more  favorable  condition  for 
combination  developed  by  the  interior  compression  due  to  this 
increase  of  density. 

We  would  also  suppose  that  the  same  assumption  would  be 
T,  ,    VI-  iustified,  in  the  case  of  hydraulic  limes  which 

Hydraulic  limes  ' 

and  pozzuolana.      are  to  receive  additions  of  pozzuolana.  This 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


189 


theory  is  not  fully  confirmed  by  experience,  winch  shows 
that  the  latter  class,  when  they  are  to  be  mixed  with  pozzu- 
olana,  may  be  slaked  by  either  the  first  or  second  process,  with 
similar  results,  and  that  the  third  process  should  invariably  be 
proscribed.  When  they  are  to  be  combined  with  inert  sand 
only,  they  should  be  slaked  by  the  first  process. 

336.  For  fat  limes,  the  second  and  third  methods  have  been 

supposed  by  many  engineers  to  possess  some 
,  1      /.  .....  ,     Supposed  advan- 

ad  vantage;  the  former,  in  conierrmg  increased    tage  of  the  second 

hardness  and  tenacity  upon  the  mortar;  the  for'^faSe^g'''^^^^^ 
latter  as  a  means  of  securing  hydraulic  proper- 
ties in  a  moderate  degree  ;  but  as  there  are  some  doubts  upon 
these  points,  particularly  as  to  the  alleged  superiority  of  air- 
slaking,  and  as  any  requisite  degree  of  strength,  hydraulic 
energy  and  quickness  may  be  conferred  upon  lime  mortars  with 
more  certainty  and  with  equal  economy,  by  the  judicious  use 
of  hydraulic  agents,  either  natural  or  artificial 
hydraulic  lime,  pozzuolana,  or  cement,  (particu-  ^^^^f^  tmtmpor^ 
larly  the  latter  in  the  United  States,)  the  first    i^nt  in  the 

United  States. 

mode  of  slaking,  inasmuch  as  it  s&  attended 

with  less  original  outlay,  gives  more  certain  results,  and  requires 

fewer  precautions  at  the  hands  of  the  workman, 

-  .       The  first  process 

may  be  regarded  as  the  most  advantageous  m    the  most  advan- 
nearly  every  case,  provided  the  precaution  is  *^seous. 
taJce7i  to  pour  on  at  the  outset  all  the  water  required  to  pro- 
duce a  stiff  paste  ^  but  no  more. 

337.  For  slaking  lime,  fresh  water  should  be        ^^^^^^  ^^^^ 
used,  sea-water  giving  in  all  cases  greatly  dimin-    for  slaking, 
ished  volumes. 

338.  General  Totten  announced  the  following  as  the  results 
of  experiments  made  at  Fort  Adams,  upon  the  different  modes 
of  extinction : 

1st.  Slakinff  by  drowning,  or  using:  a  lars^e    The  "  drowning" 

r.  .      ,  PIT.  process  weakens 

quantity  oi  water  m  the  process  of  slaking,    the  lime. 

affords  weaker  mortars  than  slaking  by  sprinkling. 


190 


PRACTICAL  TREATISE  ON  LIMES, 


2d.  Experiments  with  air-slaked  lime  were 
imratrsfactory^       too  few  to  be  decisive,  but  the  results  were 
unfavorable  to  that  mode  of  slaking. 

339.  Preservation  of  Lime. — The  paste  of  fat  lime,  whatever 
may  have  been  the  mode  of  extinction,  may  be  preserved  intact 

for  an  indefinite  length  of  time,  if  kept  from 
Ume  paTteJ'''         contact  with  the  air.    It  is  usual  to  put  it  in 

tight  casks,  or  in  reservoirs  or  trenches  covered 
up  with  sand  ;  or,  when  shed-room  is  available,  to  form  it  into 
rounded  heaps  similarly  protected  and  under  cover. 

340.  The  powder  derived  from  the  second  and  third  modes 
Preservation  of  extinction  may  be  preserved  for  several 
lime  powder.  months,  without  sensible  deterioration,  in  cov- 
ered casks  or  bins,  or  if  heaped  up  in  dry  sheds,  and  covered 
over  with  straw,  cloth,  or  dry  sand. 

341.  Until  quite  recently,  opinions  among  engineers  were 

divided  as  to  the  effect  of  time  upon  the  quality 

Gen.  Treussart.  .  p  n      t  -,      .  i        .    i -, 

01  paste  01  lat  lime,  preserved  with  suitable 
precautions  for  future  consumption.  General  Treussart  en- 
tertained the  opinion  that  they  should  be  made  into  mortar 
and  used  soon  after  their  extinction.  This  idea  finds  few  ad- 
Practice  at  the  vocates  at  the  present  day,  although  the  practice 
present  day.  in  this  country  conforms  to  it  with  singular  una- 
nimity. As  before  observed,  it  is  customary  in  some  parts  of 
the  continent  of  Europe  to  slake  the  lime  the  season  before  it 
is  to  be  used. 

342.  Fabrication  of  Mortars. — ^The  relative  quantities  in 
Fabrieation  of  which  sand  and  the  cementing  substance,  wheth- 
mortars.  the  latter  be  derived  from  common  or  hydrau- 
lic lime,  or  cement,  should  exist  in  mortar,  depend  in  a  great 
.measure  on  the  character  of  the  work  in  which  it  is  to  be 
used ;  its  locality  and  position  with  regard  to  a  state  of  moisture 
The  proportion  of  or  dryness;  and,  if  subjected  to  alternations  in 
tary'^wTth  dr'  ^^^^  respect,  the  character  of  the  moisture,  de- 
cumstances.         pending  on  its  proximity  to  or  remoteness  from 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


191 


the  sea,  the  nature  and  magnitude  of  the  forces  which  it  will 
be  required  to  resist,  the  peculiarities  of  the  climate,  and  the 
season  of  the  year  in  which  the  work  is  to  be  performed. 

343.  In  practice,  the  actual  quantities  of  the  different  in- 
gredients to  be  portioned  out  ''depend  on  the  varying  con- 
ditions of  dampness  and  dryness,  looseness  and  compactness, 
powder  and  paste,  in  which  they  may  be  measured." 

344.  The  following  data,  derived  from  the  work  of  General 
Totten  and  from  direct  trials,  will  be  found  useful  in  estimat- 
ing the  amounts  of  the  different  ingredients  necessary  to  pro- 
duce any  required  quantity  of  mortar. 

One  cask  =  240  lbs.  of  lime,  will  make  from 
.  K      1  •     n        ^     'm  One  cask  of  lime. 

7.80  to  8.15  cubic  feet  of  stiff  paste. 

One  cask  *=  308  lbs.  of  finely  ground  cement, 
will  make  from  3.70  to  3.75  cubic  feet  of  stiff  ment. 
paste ;  79  to  83  lbs.  of  cement  powder  will  make  about  one 
cubic  foot  of  stiff  paste. 

One  cubic  foot  of  dry  cement,  shaken  down,  but  not  com- 
pressed, mixed  with  .33  cubic  feet  of  water  (about        ^^^j^  ^^^^ 
2i  gallons),  will  give  .63  to  .63^  cubic  feet  of  stiff   cement  powder, 
paste  (about  4yV  gallons). 

One  cubic  foot  of  dry  cement  powder,  measured  loosely  and 
without  any  compression,  will  measure  only  .78  to  .80  cubic 
feet,  if  packed  (as  at  the  manufactorjes)  with  a  wedge-shaped 
stick  or  paddle.  The  data  given  in  the  following  table  (XIY.) 
are  compiled  from  General  Totten's  work.  The  quantities  are 
represented  by  volume. 


♦  300  lbs.  net  is  the  standard  barrel,  but  it  usually  orerruns  about  eight  lbs. 


192 


PEACTICAL  TREATISE  ON  LUVIES, 


TABLE  XIY. 


Cement 
paste. 

Sand  well 
compacted. 

.UU 

.yju 

1  Art 

.00 

.50 

.45 

1.82 

.69 

1.39 

.25 

1.00 

.68 

.91 

.18 

.71 

.78 

•78 

.00 

2.00 

.25 

2.00 

.75 

2.00 

1.00 

2.00 

Mortar  produced. 


2.02  of  mortar  with 


2.13 

(( 

4.30 

(1 

(( 

4.67 

4.30 

<( 

4.95 

(( 

(( 

5.53 

(1 

(( 

 2.25 

 1.71 

 1.07 

,  2.49 

 2.22 

,  1.85 

 1.95 

 1.57 

 1.84 

.64  water  made  2.54  grout. 
.92       "       "  3.10  " 
1.04       "       "  3.56  » 
1.22       "       "  3.76  " 
.87       "       "  2.90  " 
.87       "       "  3.05  " 
1.80  "  6.04  " 

2.01  "  "  6.60  " 
1.80  "  "  6.20  " 
1.76  "  "  6.64  " 
1.80       "       "  7.11  " 


345.  When  mortar  is  to  be  made  in  quantities  sufficiently- 
large  to  warrant  the  expense,  a  mortar  mill  of  some  approved 
pattern  should  be  provided,  for  incorporating  the  ingredients, 
as  the  mortar  thus  obtained  is  invariably  superior  to  that  pro- 
duced by  the  use  of  the  hoe  and  shovel  only. 

346.  The  mill  used  at  Fort  Warren^  Boston  harbor,  during 
the  construction  of  that  work  by  Col.  Thayer,  of  which  a  ver- 
tical section  through  the  centre  of  motion  is  given  in  Fig.  33, 
is  thus  described  by  Lieut.  W.  H.  Wright,  in  his  "  Treatise  on 
Mortars,"  page  98  :    "  It  consists  of  a  circular  trench  built  of 

masonry,  with  slopins:  sides.     In  the  trench 

Description  of  '  i      i        /.        •  t 

mortar  mill  driven  rests  a  heavy  wheel,  8  feet  m  diameter,  lur- 
by  horse-power.  njgj^ed  with  a  tire  \  inch  thick  and  12  inches 
broad,  and  loaded  by  having  its  interior  space  filled  with 
sand.  At  the  centre  of  motion  is  a  drum,  or  circular  mass 
of  masonry,  4  ft.  8  in.  in  diameter,  in  which  is  firmly  fixed  a 
vertical  axis  about  8  inches  square.  With  this  axis  is  con- 
nected th'?  horizontal  shaft  (also  about  8  inches  square),  which 


HYDEAULIO  CEMENTS,  AND  MORTAES.  193 

passes  through  the  centre  of  the  wheel,  and  to  which  the 
horse  is  attached. 


Fig.  33. 


"  The  distance  from  the  centre  of  motion  to  the  centre  of  the 
wheel  or  trench  is  7  ft.  6  in.,  and  the  radius  of  the  horse- 
path is  20  ft. 

"  The  space  comprised  between  the  drum  and  trench  is  use^ 
as  a  reservoir  for  the  slaked  lime.     It  is  sufficiently  capa- 
cious to  contain  the  paste  which  sixteen  casks  of  lime  will 
afford,  and  is  conveniently  divided,  by  means  of  movable 
radial  partitions,  into  sixteen  equal  parts ;  so 
that  the  laborer,  who  prepares  the  mortar,  is  J^^ued!'*'^''' 
relieved  of   the  necessity  of  measuring  the 
paste. 

The  mill  is  protected  from  the  weather  by  a  cheap  roof;  it 
is  placed  in  the  vicinity  of  a  pump,  immediately  under  the 
spout  of  which  stands  a  box,  7  ft.  long,  5  ft.  broad,  1  ft.  4J- 
inches  deep,  used  for  slaking  the  lime.  This  box  is  connected 
at  one  extremity  with  a  small  compartment,  in  the  bottom  of 
which  is  an  iron  grating,  which  allows  the  fluid  paste  to  pass 
out  into  the  reservoir,  but  retains  the  stones  and  imperfectly 
slaked  lumps  of  lime.  During  the  process  of  slaking,  the 
compartment  is  separated  from  the  rest  of  the  box  by  a 
13 


194 


PEACTICAL  TEEATISE  ON  LIMES, 


movable  board,  which  slides  in  grooves  made  water-tight 
with  a  little  of  the  lime  putty. 

"  The  board  being  in  its  place,  water  is  pumped  into  the 
box  in  sufficient  quantity  to  convert  the  lime,  (three  casks  at 
once,)  into  a  thin  cream  that  will  readily  run  off  through  the 
grating.  The  lime  is  then  added  and  well  stirred,  in  order 
to  break  up  the  lumps,  a  large  hoe  being  usually  employed 
for  the  purpose.  When  the  slaking  is  completed,  the  sliding 
board  is  raised,  and  the  cream  conveyed  by  means  of  the 
trough,  E,  attached  to  the  grating  for  the  purpose,  to  the 
basin,  F,  w^here  it  is  allowed  to  remain  as  long  as  possible 
before  it  is  used." 

This  mill  is  capable  of  making  six  hundred  cubic  feet  of 

mortar  per  day  of  ten  hours.  By  increasing 
Capacity  of  mill.     the  radius  of  the  trench  to  12^  ft.,  and  the 

radius  of  the  horse-path  to  25  ft.,  the  working 
capacity  of  the  mill  would  be  nearly,  if  not  quite,  doubled. 

347.  The  other  implements  that  will  be  found  convenient  in 
the  preparation  of  mortar  are  a  hoe  and  shovel,  differing  little, 
if  at  all,  from  the  ordinary  form ;  a  box  for  measuring  lime 

and  cement  paste,  which  should  be  of  conven- 
requL'r^'"'''''*'    ient  capacity,  say  3  cubic  feet,  and  should  be 

arranged  with  handles  projecting  horizontally 
on  two  opposite  sides,  like  those  of  a  hand-barrow,  and  a  sec- 
ond box  of  the  same  size  as  tlie  foregoing,  or  rather  a  little 
larger  (say  3|-  cubic  feet  in  capacity),  so  that  it  will  contain, 
loosely  thrown  in  and  struck,  a  volume  of  sand  corresponding 
to  three  cubic  feet  well  compacted.  This  box  may  be  provided 
with  handles  like  the  other,  but  had  better  be  arranged  on  a 
wheel-barrow. 

348.  To  make  mortar  with  the  mill  above  described,  the 

lime  paste  is  first  put  into  the  trench  from  one 
morta'r^"''^^    of  the  central  compartments.    To  this  is  added 

by  measurements  from  the  wheel-barrow  box, 
about  one-half  of  the  sand  required  for  the  batch,  and  the  mil] 


HYDEAULIC  CEMENTS,  AND  MORTAES. 


195 


i3  then  set  in  motion,  and  the  ingredients  thoroughly  incorpor 
ated.  The  remainder  of  the  sand  then  follows,  with  such 
additions  of  water  as  may  be  necessary  to  bring  the  mass  to 
the  proper  consistency.  When  lime  mortar  is  to  be  rendered 
hydraulic  by  the  use  of  cement  or  of  an  alkaline  silicate,  these 
had  better  be  added — the  cement  in  powder  and  the  silicate  in 
solution — to  the  lime  paste  just  before  the  mill  is  set  in  motion, 
in  order  that  the  mixing  may  be  thorough  and  complete  ;  ex- 
cept in  the  case  of  very  quick-setting  cement,  when  its  incor- 
poration into  the  mortar  should  be  deferred  until  the  last  por- 
tions of  sand  are  added. 

349.  This  process  of  slakinsj  the  lime  with  an    ^        ^  ^ 

^  °  Excess  of  water 

excess  of  water  was  never  employed  at  Fort  War-  not  used  in 
ren,  except  when  hydraulic  cement  was  to  be  ^^^^^^s- 
added  to  the  mortar.  For  mortars  composed  of  lime  and  sand 
only,  the  lime  was  slaked  in  the  ordinary  way  with  a  sufficiency 
of  water,  simply  to  produce  a  thick  pulp.  The  result  given  in 
Table  XIIL,  page  185,  which  may  be  easily  verified  on  a  large 
scale,  indicate,  apparently  beyond  a  doubt,  that  with  the  limes 
most  extensively  in  use  for  public  works  on  our  Atlantic  coast, 
the  largest  augmentation  of  volume  in  slaking  is  secured  by 
adhering  to  the  following  directions,  viz.:  put  the  lime  into  a 
box,  break  up  the  larger  lumps  with  a  hammer ;  pour  in  at 
once  the  quantity  of  water  (ascertained  previously  by  trial) 
necessary  to  reduce  them  to  a  stiff  paste,  and 
then  cover  up  the  box  so  as  to  prevent,  as  ^sedln  Xking.^^ 
much  as  possible,  the  escape  of  heat  and  vapor, 
allowing  it  to  remain  in  that  condition,  without  stirring,  until 
the  reduction  is  complete.  In  order  to  connect  this  process 
with  the  operations  of  a  mortar-mill,  it  might  be  necessary  to 
provide  several  boxes,  so  that  the  lime  might,  in  all  cases, 
have  at  least  forty-eight  hours  to  digest  before  it  is  made  into 
mortar. 

350.  Major  E.  B.  Hunt,  Corps  of  Engineers,  formerly 
charged  with  the  construction  of  Fort  Taylor,  Key  West, 


196 


PEACTICAL  TREATISE  ON  LIMES, 


Florida,  has  kindly  furnished  me  the  following  description  of 
the  steam  mortar-mill  in  use  at  that  work. 


levation  of  Mortar-Mill. 
Fig.  34. 

351.  The  steam  mortar-  /  ill  which  was  erected  at  Fort  Tay- 
lor   in  1857, 

Steam  mortar 
mill. 


is  of  the  kind 
devised  by 
the  late  Brevet-Major  J. 
Sanders,  and  was  pur- 
chased and  set  up  un- 
der his  direction.  The 
mill  and  engine  were 
made  by  E.  C.  Stotsen- 
berg,  Wilmington,  Del- 
aware, and  cost  $3,466. 
The  frame  and  house  for 
the  mill,  and  setting  them 
up   cost  $237,  to  which 


Plan  of   bed-plate  ;  scale  i  in.  to  1  foot. 
Ym.  35. 


Bhould  be  added  the  freight  and  cost  of  engine-house,  making 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


197 


nearly  $5,000  as  the  cost  of  the  whole  m  work-    Description  of 

1  rrn  •        •       1  •  same. 

mg  order.  ine  engine  is  about  sixteen  to 
twenty  horse-power,  and  has  a  heavy  fly-wheel.  Two-thirda 
of  this  powxr  would  run  the  mill,  though  at  greater  cost  foi 
fuel  and  at  higher  pressure.  The  engine  is  geared  into  a  fixed 
connection  with  the  mortar-mill,  which  is  a  fault,  as  the  engine 
cannot  be  used  for  any  other  purpose,  without  driving  the  mill, 

The  mill.  Figs.  34  and  35,  consists  essentially  of  a  pan 
geared  into  a  cogged  connection  with  the  engine,  and  support- 
ed on  large  conical  bed  rollers  ;  and  of  a  pair  of  hollow  cast- 
iron  wheels,  so  joined  by  an  axle,  that  they  revolve  in  the 
opposite  sides  of  the  pan  with  the  same  velocity  as  the  pan 
itself.  The  grinding  surfaces  have  thus  a  compound  or  double 
velocity.  Two  helical  scrapers  are  fixed  to  the  vertical  driving 
shaft  of  the  wheels,  and  are  so  shaped  as  to  throw  a  sort  of 
furrow  in  the  mortar  materials  when  mixing.  A  scraper  is 
fixed  to  each  end  of  the  horizontal  shaft,  so  as  to  scrape  the 
faces  of  the  large  wheels  as  they  roll  around  that  shaft. 
Another  scraper  is  also  fixed  to  this  axle,  so  as  to  scrape  the 
inner  face  of  the  pan  and  to  throw  a  furrow  towards  the  centre. 

The  lime  paste  is  first  put  in  the  pan,  and  is  ground  while 
the  sand  and  cement  are  measured  out,  on  a  fixed  platform  at 
the  level  of  the  bottom  of  the  pan  and  bordered 
up  close  to  its  rim.    The  mixed  cement  and    t^rS.""^ ''''''^ 
sand  are  shovelled  in,  and  water  added  until 
the  whole  batch  is  introduced.    The  greatest  resistance  is 
encountered  when  the  dry  materials  are  thrown  in,  at  which 
time  the  speed  is  very  much  slackened,  and  the  engine  requires 
nearly  its  full  power  at  the  working  pressure,  if  the  filling  be 
done  very  rapidly.    As  the  mixing  proceeds,  the  speed  of  rev- 
olution quickens  greatly,  but  is  controlled  by  the  engine- 
driver  in  proper  limits. 

Wlien  the  batch  is  sufficiently  ground  and  mixed,  it  is 
scooped  out  by  the  use  of  a  scoop-shovel,  the  workman  stand- 
ing on  a  lower  portion  of  the  platform,  about  a  foot  below  the 


198 


PRACTICAL  TREATISE  ON  LIMES, 


bottom  of  the  pan,  and  throwing  tlie  mortar  into  a  mortar-box 
wliich  is  backed  in  by  a  sling  cart,  so  arranged  as  to  carry  the 
batch  to  the  derrick  or  point  of  use,  and  then  to  rim  the  box 
down  to  the  ground  by  two  screws  with  arras  and  long  links, 
one  at  the  fore  and  one  at  the  near  end  of  the  box.  Each 
batch  of  mortar  corresponds  to  one  barrel  of  cement,  and  the 
mill  has  repeatedly  made  over  fifty  batches  in  a  day,  and  can 

do  this  as  a  regular  day's  work.  It  requires 
worrtii^miif  engine-driver,  one  fireman,  and  from  two  to 

five  men  at  the  mill,  according  to  the  amount 
of  mortar  to  be  made.  It  has  also  been  used  during  the  last 
and  present  season  to  make  the  mortar  for  concrete,  which  is 
transported  by  the  sling  cart,  hoisted  by  the  derrick  on  the  con- 
crete platform,  and  then  thrown  over  the  broken  stone  spread 
out  to  receive  it.  Two  turnings*  mixed  it  very  well.  The 
broken  s^one  is  hoisted  by  a  light  platform  carrying  five 
barrels,  the  usual  amount  for  a  batch.  This  using  it  for  con- 
crete as  well  as  for  masonry  mortar,  will  often  make  running 
the  mill  an  economy,  when  it  would  not  be  so,  were  only  the 
mortar  for  masons  made  there.  It  will  hardly  be  found  an 
economy,  to  run  the  mill  for  less  than  twenty  to  twenty-five 
batches  a  day. 

The  mortar  made  in  this  mill  is  very  much  better  than  that 

made  by  hand  from  the  material  found  at  Key 

Quality  of  mill-  'W'est,  as  the  coarse  calcareous  sand  requires 
made  mortar.  '  ^ 

pulverization  to  make  the  mortar  work  well. 

It  is  what  the  masons  call  "  woolly,"  when  made  by  hand,  and 

requires  a  much  larger  dose  of  cement  or  lime,  to  work  properly 

under  the  trowel. 

The  brick- work  joints  with  mill-made  mortar  are  observ- 
ably thinner  than  with  the  hand-made  mortar,  thus  giving  a 
saving  of  mortar  per  cubic  yard. 

The  gain  by  using  the  mill,  is  rather  in  the  superior  qual- 

*  These  turnings  are  described  in  the  third  step  of  the  method  of  manipulation 
practised  at  Forts  Richmond  and  Tompkins,  New  York.  (Paragraph  369.) 


HiTDEAULIC  CEMENTS,  AND  MORTAKS. 


199 


ity  and  saving  of  quantity  of  the  mortar,  than  Advantage  of 

in  the  cost  of  mixing,  though,  when  large  oper- 

atives  are  steadily  maintained,  there  is  a  great  gain  under  this 

head,  when  circumstances  favor  its  easy  distribution. 

Ordinarily,  a  batch  needs  to  be  g^round  not    ^.         .   ,  . 

"  ^  °  Time  required  m 

less  than  seven  minutes,  and  not  beyond  fifteen    making  mortar 

i  1       •        IT  •  -1        with  the  mill. 

m mutes  irom  the  time  the  hme  paste  is  put  in  the 
pan.  If  the  grinding  be  carried  much  beyond  this  time,  the 
mortar  is  decidedly  impaired,  and  sets  very  slowly.  Tliis  is 
ascribed,  in  part,  by  Major  Hunt  to  the  extreme  pulverization 
of  the  calcareous'  sand,  whereby  the  void  spaces  are  made 
all  small  and  nearly  uniform,  and  partly  to  the  incessant 
breaking  up  of  the '  incipient  setting  by  long  continued 
grinding." 


Fig.  36. 


352.  Another  mortar-mill.,  successfully  used  by  the  designer, 
M.  Greyveldinger,  on  the  works  connected  with  the  drainage 
of  the  Boulevard  de  Sevastopol,  Paris,  is  repre- 
sented by  Fig.  36 ;  it  consists  of  a  hopper  of  ^;,g^er?mm. 
Sheet-iron,  A,  closed  at  the  bottom  by  a  disk, 
B,  surmounted  with  a  cone,  C ;  the  disk  and  cone  receive  a 
rapid,  rotary  motion  by  means  of  the  cogwheel  D.  The 
hopper  is  provided  with  a  rectangular  opening,  E,  ]•  of  a  metre 
(7.9  inches)  in  width,  and  of  which  the  height  can  be  varied  at 


200 


PRACTICAL  TEEATISE  ON  LIMES, 


pleasure  by  means  of  a  sheet-iron  slide  controlled  by  a  ratchet 
and  cog-wheel,  F.  Below  the  hopper,  is  a  cylindrical  spout, 
G,  containing  a  revolving  screw,  to  the  core  of  which,  iron 
points  are  attached  at  regular  intervals.  Jets  of  water  regu- 
lated at  pleasure  by  hand,  by  means  of  the  stop-cock  K,  are 
let  into  the  funnel  J,  at  the  bottom,  through  a  hose  leading  to 
a  reservoir  of  water. 

353.  The  dry  ingredients  of  the  mortar  having  first  been 
roughly  mixed  with  a  shovel,  and  if  necessary,  passed  through 
a  screen,  are  introduced  into  the  hopper.  The  rotation  of  the 
disk  and  cone  completes  the  incorporation  of  the  dry  mate- 
rials, and  imparts  to  them  a  centrifugal  motion  which  in- 
sures a  constant  flow  from  the  opening  E,  into  the  funnel  J, 
where  they  receive  the  requisite  supply  of  water,  and  pass  into 
the  spout  G.  The  motion  of  the  screw  carries  the  mortar  to 
the  other  end  of  the  spout,  completes  the  mixture,  and  dis- 
charges it  into  barrows  or  buckets  placed  to  receive  it.  M. 
Greyveldinger  had  four  buckets  arranged  on  a  revolving  plat- 
form, M.  By  means  of  the  crank  the  buckets  are  passed 
under  the  opening  in  the  spout,  and  thus  tilled  in  succession 
without  w^asting  the  mortar  or  arresting  the  motion  of  the 
machine.    Two  men  at  the  crank  L,  can  work  the  machine. 

354.  At  the  Boulevard  de  Sevastopol,  Paris,  motion  was 
derived  from  a  one-half  horse-power  engine,  by  means  of  a 
belt  working  on  the  drum,  O. 

355.  There  were  required  to  tend  the  machine  eight  labor- 
Force  required  to  ers,  to  measure  the  materials,  fill  the  hopper, 
^^^^  take  away  the  mortar,  &c.,  one  intelligent  fore- 
man to  regulate  the  opening  in  the  hopper  and  the  supply  of 
water,  and  one  engineer. 

356.  The  average  daily  expense,  neglecting  the  wear  and 
tear,  is  as  follows : 


HYDKAULIC  CEMEOTS,  AND  MORTAKS. 


201 


Nine  men  at  three  francs           -         -         -  fr.  27 

One  engineer,  -  4 
Coal  2 


33=$6.10 

357.  The  capacity  of  the  machine  was  thirty 

-  .  r.      1  .  1  N  "Its  capacity, 

cubic  metres  (38.3  cubic  yards)  oi  mortar,  per 

day,  of  ten  hours.    Cost  of  making  one  cubic  metre,  1.10  fr., 

and  of  one  cubic  yard,  sixteen  cents. 

358.  Estimating  the  laborers  at  ninety-one  cents  per  day,  the 
engineer  at  $1.50,  and  supposing  the  other  expenses  to  remain 
the  same,  the  cost  of  making  one  cubic  yard  of  ^Qg^  making 
mortar  would  be  twenty-eight  cents.  The  cost  mortar  with  it. 
of  making  the  mortar  at  Fort  Warren,  with  the  mill  consisting 
of  a  heavy  wheel  turning  in  a  circular  trough  by  horse-power, 
and  labor  at  ninety-one  cents  per  day,  was  thirty-nine  cents 
per  cubic  yard.  Mr.  G.'s  mill  will  answer  for  the  quickest  set- 
ting cements,  as  only  eight  seconds  of  time  elapse  after  the 
materials  receive  the  water,  before  the  mortar  is  discharged  in- 
to the  buckets. 

359.  Extensive  operations  requiring  large  quantities  of  mor- 
tar are  frequently  carried  on  by  experienced  engineers,  without 
the  aid  of  a  mortar-mill  of  any  kind.    When    jj^king  mortar 
ordinary  lime  mortars  are  thus  made  by  hand,    ^7  i^^^- 

it  is  customary  and  convenient  to  slake  the  lime  by  the  first 
method  described,  and  in  no  greater  quantity  than  may  be  re- 
quired for  immediate  use.  The  operation  should  be  conducted 
under  a  shed.  The  measure  of  sand  required  for  the  "batch" 
is  first  placed  upon  the  floor,  and  formed  into  a  basin  for  the 
reception  of  the  unslaked  lime.  After  this  the  latter  is  put  in, 
and  the  larger  lumps  broken  up  with  a  mallet  or  hammer ;  the 
quantity  of  water  necessary  to  form  a  stiff  paste  is  let  on,  from 
the  nozzle  of  a  hose,  or  with  watering-pots,  or 
even  ordinary  buckets.  The  lime  is  then  stir-  of  slaMng^Sne^^ 
red  with  a  hoe,  as  long  as  there  is  any  evolution 
of  vapor,  after  which  the  ingredients  are  well  mixed  together 


202 


PEACTICAL  TEEATISE  ON  LIMES, 


with  the  shovel  and  hoe,  a  little  water  being  added  occasionally 
if  the  mass  be  too  stiff.  At  this  stage  of  the  operation,  it  is 
customary  to  heap  the  mortar  compactly  together,  and  allow  it 
to  remain  until  required  for  use.  When  circumstances  admit, 
it  should  not  be  disturbed  for  several  days,  and  during  the  pe- 
riod of  its  consumption  should  be  broken  down  and  "  temper- 
ed" in  no  larger  quantities  than  may  be  required  for  use  from 
day  to  day. 

^  360.  It  is  believed  that  certain  slight  modifi 

dons^recommend-    cations  of  this  common  method  of  procedure 
can  be  made,  with  decided  advantage  in  the 
final  results.    They  may  be  indicated  as  follows  : 

361.  First.  All  the  lime  necessary  for  any  required  quantity 
of  mortar  should  be  slaked  at  least  one  day  be- 

Slake  the  hme  at  .    .    .  i      •  i  i 

least  one  day  be-     Tore  it  IS  incorporated  With  the  sand. 

fore  it  is  wanted.       g^^.  Second.  The  sand-basin,  to  receive  the 

unslaked  lime  should  be  coated  over  on  the  in- 
In  a  water-tight        .  i       .  t    t  ,  i  c 

basin.  Side  With  lime-paste,  to  prevent  the  escape  oi 

water. 

AH  the  necessary       363.  Third.  All  the  water  required  to  slake 

water  to  bo  pour-      ,1.  .pr, 

ed  on  at  once.        the  lime  to  a  stiii  paste,  should  be  poured  on  at 
once.  This  will  completely  submerge  the  quick- 
lime.   The  heap  should  then  be  covered  over  with  tarpaulin 
or  old  canvas,  and  left  until  next  day. 

364.   Fourth.   The  ingredients  should  be 

Mix  ingredients,  i  i        •     i        i    i  i  i 

and  heap  up  for     thoroughly  mixed,  and  the  mortar  heaped  up 

for  future  use. 

365.  The  mortar  used  by  Lieut.-Col.  J.  G.  Barnard,  Corps  of 
Engineers,  in  the  construction  of  Forts  Richmond  and  Tomp- 
kins, ]^ew  York  harbor,  was  made  by  hand.  When  required 
for  stone  masonry,  or  concrete,  it  was  composed  of  hydraulic 
cement  and  sand,  without  lime. 

366.  *Each  batch  of  mortar,  or  concrete,  corresponded  to  one 


*  These  data  were  furnished  by  Captain  M.  D.  McMester,  of  the  Engineers,  at 
that  time  Assis^tant  to  Lieutenant-Colonel  Barnard,  Corps  of  Engineers. 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


203 


cask,  or  308  pounds  net,  of  hydraulic  cement  powder.  Four 
men  constituted  a  fi^an^  for  measuring:  out  and       ^,  .  r 

^     "  ^  Method  of  mamp- 

raixing  the  ingredients,  who  proceeded  to  the  uiation. 
several  steps  of  the  process  in  the  following  order : 

367.  First  The  sand  is  spread  in  a  rectangu-    ^.^  ^^^^ 

lar  layer  of  two  inches  in  thickness.  naent  together, 

dry. 

368.  /Second.  The  dry  cement  is  spread  equal- 
ly all  over  the  sand. 

369.  Third.  The  men  place  themselves,  shovel  in  hand,  two 
on  each  side  of  the  rectangle,  at  the  angles,  incorporating  the 
facing  inwards.  Furrows  of  the  width  of  a  ingredients, 
shovel,  are  then  turned  outwards  along  the  ends  of  the  rectan- 
gle, until  the  whole  bed  is  turned.  The  two  men  on  one  side 
thus  find  themselves  together,  and  opposite  the  two  on  the 
other  side,  having,  of  course,  left  a  vacant  space  transversely 
through  the  middle,  of  double  the  width  of  a  shovel.  They  then 
move  back  to  their  original  positions  in  turning  furrows  as  be- 
fore, when  the  bed  occupies  the  same  space  that  it  did  previ- 
ous to  the  first  turning.  The  turning  is  executed  by  succes- 
sively thrusting  the  shovel  under  the  material,  and  turning  it 
over  about  one  angle  as  a  pivot.  Each  shovel  thus  moves  to 
the  middle  of  the  bed,  where  it  is  met  by  the  one  opposite, 
when  each  man  moves  back  to  the  side  in  dragging  the  edge 
of  his  shovel  over  the  furrow  he  has  just  turned. 

370.  Fourth.  A  basin  is  formed,  by  drawing  all  the  mate- 
rial to  the  outer  edsre  of  the  bed.  .  , 

^  .  ,  Adding  the  water. 

371.  Fifth.  The  water  is  poured  into  the 
basin  thus  formed. 

372.  jSixth.  The  material  is  thrown  back  upon  the  water, 
absorbing  it,  when  the  bed  occupies  the  same  space  that  it  did 
at  the  beginning. 

373.  Seventh.  The  bed  is  turned  twice,  by  the  process 
described  above.  If  required  for  mason's  use,  the  mortar  is 
then  heaped  up,  to  be  carried  when  and  where  required.  If  for 
concrete,  (the  mortar  occupying  the  rectangular  space,  as  at  first). 


204 


PJiACTICAL  TEEATISE  ON  LIMES, 


Ooncreta  ^^9^^^'  broken  stones  are  spread 

equally  over  the  bed. 

375.  Nvnth.  A  bucket  of  water,  more  or  less,  (depending 
upon  the  quantity  of  stones,  their  absorbing  power,  and  the 
temperature  of  the  air),  is  sprinkled  over  the  bed. 

376.  Tenth.  The  bed  is  turned  once  as  before,  and  then 

heaped  up  for  use.     The  act  of  heaping  up, 

bX^stone^s*^^     Wl^^^^       ^^^^  ^^^^^  ^^^^^  ^ 

second  turning. 

377.  The  time  consumed  in  making  a  batch  of  mortar  is  a 
little  less  than  twenty  minutes;  in  incorporating  the  broken 
stones,  ten  minutes  more. 

378.  When  the  mortar  is  required  in  very  small  quantities, 
to  avoid  deterioration,  instead  of  proceeding  to  the  fourth  step 
of  the  manipulation,  the  mixture  of  cement  and  sand  is  heaped 
up,  and  the  water  added  and  paste  formed  with  the  hoe,  in  sudh 
quantities  as  are  required. 

379.  Composition  of  Mortar. — The  mortar  at  Forts  Rich- 

mond and  Tompkins,  whether  required  for  stone 
^emortar.^         masonry  or  for  concrete,  contained  one  cask*  (or 

308  pounds  net)  of  hydraulic-cement  powder, 
which  produced  3.70  to  3.75  cubic  feet  of  stiff  paste  ;  and  three 
casks,  or  about  twelve  cubic  feet  of  loose  sand,  equal  to  2.44  casks 
(about  9.75  cubic  feet),  well  compacted.  These  ingredients 
being  incorporated,  produced  11.75  cubic  feet  of  rather  thin 
mortar. 

380.  Convposition  of  Mortar  used  at  Fort  Warren. — The 

mill-made  mortar  for  the  st07ie  masonry  at  Fort 

Composition  of 

the  Fort  Warren     Warren  w^as  composed  of  lime,  hydraulic  ce- 
ment, and  sand,  in  the  following  proportions,viz/. 

One  cask  dry  cement  (325  lbs.  net),  producing  3.75  to  3.85  cub.  ft.  of  stiff  paste. 
O/ie-AaZ/ cask  of  Rockland  lime  (120  lbs.  net),  producing  four  cub.  ft.  of  stiflf  paste. 
Nineteen  md  one-fourth  cubic  feet  of  loose  sand,  equal  to  fourteen  and  a  half 
cubic  feet  well  compacted. 


*  The  average  net  weight  of  a  barrel  of  cement  is  308  pounds. 


HYDEAULIC  CEMENTS,  AND  MOKTAES.  205 


These  ingredients  being  well  mixed,  make  eighteen  and  a 
half  cubic  feet  of  good  mortar. 

For  mortar  for  hrick  masonry,  the  same  quantities  of  lime 
and  cement  received  but  fifteen  and  three-quarters  cubic  feet 
of  loose  sand,  equal  to  twelve  cubic  feet  well  compacted,  giving 
sixteen  cubic  feet  of  good  mortar. 

Estimating  the  cost  of  the  lime  at  .70  cents  per  cask  of  240 
lbs.  net,  the  cement  at  $1.62^  per  cask  of  325  lbs.  net,  and  the 
sand  at  .50  cents  per  gross  ton,  labor  at  .91  cents,  and  horses 
.40  cents  per  day  of  ten  hours,  and  we  have  the  following 
analysis  of  the  cost  of  the  two  kinds  of  mortar  used  at  Fort 
Warren : 

MORTAR  FOR  STONE  MASONRY. 
Mortar  for  ^  ^^^^  cement,  325  lbs.  net=385  cubic  feet  of  paste,  at 


stone  masonry.  $1.62^  $1,630 

\  cask  lime^four  cubic  feet  of  paste,  at  70c  350 

14.61  cubic  feet  sand,  at  50c.  per  ton  496 

Labor  of  men,  at  91c.  per  day  245 

Labor  of  horse,  at  40c.  per  day    028 


Total  cost  of  a  batch  of  18^  cubic  feet  of  mortar,  corresponding  to  one 

cask  of  cement   $2.15 

Cost  of  1  cubic  foot  of  mortar   ,14^ 

"      1    "    yard       "    3.93 

MORTAR  FOR  BRICK  MASONRY. 

Mortar  for  ^        oement,  at  $1.63  $1.63 

brick  masonry.     \  cask  lime,  at  10c  35 

12  cubic  feet  sand,  50  c.  per  ton  409 

Labor  of  men,  91c.  per  day  208 

"     horse,  40c.  per  day  024 


Total  cost  of  a  batch  of  mortar  of  16  cubic  feet,  corresponding  to  one 

cask  of  cement   2.621 

Cost  of  1  cubic  foot  of  mortar  16^ 

"     1    "    yard       "    4.40 


381.  Some  engineers  object  to  the  use,  in  works  of  impor- 
tance, of  mortar  containing  so  large  a  proportion  of  sand  as  that 
adopted  at  Forts  Richmond  and  Warren  ;  others  again  very  sel- 
dom add  lime  to  their  cement  mortars.  Touching  this  last-men- 
tioned point,  recent  experiments  show,  with  a  uniformity  quite 
satisfactory,  that  most  American  cements  will  sustain,  without 


206 


PEACTICAL  TREATISE  ON  LIMES, 


any  great  loss  of  strength,  a  dose  of  lime  paste  equal  to  that  of 
the  cement  paste  ;  while  a  dose  equal  to  -J  to  f  the  volume  of 

cement  paste  may  safely  be  added  to  any  ener- 
Ume^that  may  be  getic  Rosendale  cement,  without  producing  dete- 
monars?  rioration  in  the  quality  of  the  mortar,  to  a 

degree  requiring  any  serious  consideration. 
JSTeither  is  the  hydraulic  activity  of  the  mortars  so  far  impaired 
by  this  limited  addition  of  lime  paste,  as  to  render  them  unsuita- 
ble for  concrete,  under  water  or  other  submarine  masonry ; 
while,  for  constructions  not  subject  to  immediate  submersion, 
or  the  action  of  the  returning  tide,  it  is  to  be  preferred  on  many 

accounts.  By  the  use  of  lime,  we  secure  the 
of  the^Ume^^^^      double  advantages  of  a  rather  slow  mortar — one 

that  is  in  no  danger  of  setting  before  it  reaches 
the  mason's  hand — and  a  cheap  mortar.  We  also  avoid  the 
principal  serious  objection  to  the  use  of  a  quick-setting  mortar, 
due  to  careless  and  tardy  attendance  on  the  masons,  and  conse- 
quently the  constant  breaking  up  of  the  incipient  set  on  the 
mortar-board,  whereby  cements  are  degraded  in  energy  to  a 
level  with  ordinary  hydraulic  limes. 

382.  If  the  lime  paste  had  been  replaced  by  cement  paste  in 

the  Fort  Warren  mortars,  the  mortar  for  stone 

Comparison  of  ce- 
ment and  of  lime    masonry  would  have  cost  $5.96  instead  of  $3.93 

mor  t^i*s 

per  cubic  yard,  and  that  for  brick  masonry 
$6.69  instead  of  $4.40 ;  while  if  lime  paste  had  been  used  ex- 
clusively, the  cost  would  have  been  only  $2.53  for  the  first, 
and  $2.72  for  the  second. 

383.  In  extensive  operations  it  is  well  to  have  a  mortar-box 

and  cai't  for  transporting  the  mortar  from  the 
Mortar-box  and      ^.-^^  work.    The  box  should  be  made 

of  stout  planks,  and  be  about  5|-  feet  long, 
feet  wide,  and  9  to  10  inches  deep,  and  so  arranged  that 
it  can  be  readily  slung  up  underneath  the  cart,  by  means  of  a 
windlass.    Figs.  37,  38,  and  39  represent  the  cart  and  box  used 
with  entire  satisfaction  at  Fort  Warren  and  elsewhere. 


HYDRAULIC  CEMENTS,  AND  MOKTARS.  207 


Fig.  37. 


Fi-.  39. 


Why  "pointing 
is  necessary. 


POUsTTING  MOETAR. 

384.  In  laying  up  masonry  of  any  character,  whether  with 
common  or  hydraulic  mortar,  the  exposed  edges  of  the  joints  will 
naturally  be  deficient  in  density  and  hardness, 
and,  therefore,  unable  to  withstand  the  destruc- 
tive action  of  the  elements ;  particularly  varia- 
tions in  temperature,  producing  extremes  of  heat  and  cold.  It 
is  therefore  customary,  to  fill  the  joints  as  compactly  as  possi- 
ble, to  the  depth  of  about  half  an  inch,  with  mortar  prepared 
especially  for  the  purpose.  This  operation  is  called  '''' jpointing^' 
and  the  mortar,  jpointing  mortary  The  cleaning  out  of  the 
joints  to  the  requisite  depth  should  take  place  while  the  mortar 


208 


PRACTICAL  TREATISE  ON  LIMES. 


is  new  and  soft ;  and  (in  stone  masonry)  when  the  stones  come 
in  contact,  or  nearly  so,  the  joints  mnst  be  enlarged,  to  the 
width  of  about  three-sixteenths  of  an  inch  by  a  stone-catter. 
385.  Pointing  mortar  is  compounded  of  a  paste  of  finely 
erround  cement,  and  clean  sharp  silicious  sand. 

Composition  of         .  >  ^  ^ 

"  pointing  in  such  proportions  that  the  volume  of  cement 

paste  shall  be  very  slightly  in  excess  of  the 
volume  of  voids  in  the  sand.  These  voids  should  be  care- 
fully ascertained.  The  measure  of  sand  will  generally 
vary  between  2^  and  2f  that  of  the  cement  paste;  or  by 
Aveight,  one  of  cement  powder  to  from  3  to  3J  of  sand.  The 
mortar,  when  ready  for  use,  should  appear  rather  incoherent 
and  quite  deficient  in  plasticity.  The  mixing  should  take 
place  under  shelter,  in  an  iron  or  stone  mortar,  or  some  other 
suitable  vessel,  and  in  quantities  of  not  over 
Made  np  in  small    two  or  three  pints  at  a  time. 

quantities.  •  . 

386.  Before  pomtmg,  the  wall  should  be  thor- 
The  wa  1  should  oughly  saturated  with  water,  and  kept  in  such 
6^ore  pointing,  ^  Condition,  that  it  will  neither  absorb  water 
and  not  allowed      from  the  mortar,  nor  impart  any  to  it, — two 

to  dry  rapidly  ^  ^  ...  . 

afterwards.  conditions  of  special  importance,  the  first  being 

paramount. 

Walls  should  not  be  allowed  to  dry  too  rapidly  after  point- 
ing, but  should  be  kept  moist  for  several  days,  or  better  still, 
for  two  or  three  weeks.  Pointing  in  hot  weather  should  there- 
fore be  avoided,  if  possible ;  or  else  some  temporary  shelter 
from  the  direct  action  of  the  sun's  rays  should  be  provided. 

38Y.  For  pointing  masonry  in  courses,  the  tools  required  be- 
sides an  ordinary  mason's  trowel  are,  a  straight- 
en pointS^^^^^  edge?  ^b^^t  six  feet  long ;  a  caulking  iron, 
measuring  three  inches  by  one-eighth  of  an 
inch  on  the  edge ;  a  hammer,  and  some  conveniently  shaped 
iron  or  steel  instrument  for  polishing  the  surface  of  the  joint 
in  the  last  stage  of  the  operation.  The  mortar  is  put  in 
the  joint  with  the  trowel,  the  straight-edge  being  placed 


HYDRAULIC  CEMENTS,  AKD  MOETAES.  209 


against  the  wall,  just  below  the  joint,  as  an  Manner  of  using 
auxiliary.  The  joint  is  then  well  caulked  with 
the  caulking  iron,  by  repeated  blows  of  the  hammer,  until  a 
film  of  water  shows  itself  on  the  surface  of  the  mortar  ;  after 
which,  mortar  is  again  put  in,  and  the  caulking  repeated.  In 
using  the  straight-edge,  two  men,  one  at  each  end,  can  conveni- 
entlj  work.  The  operation  is  continued  until  the  joint  is  entire- 
ly full.  The  mason  then  rubs  and  polishes  the  joint,  under  as 
great  a  pressure  as  he  can  exert,  and  finishes  off  by  using  the 
straight-edge  and  trowel  point,  to  remove  any  mortar  spread 
out  upon  the  stones  on  either  side,  make  the  pointing  straight, 
and  give  the  appearance  of  exact  equality  in  the  thickness  of 
the  joints. 

388.  In  pointing  rubble  masonry,  the  same  general  direc 
tions  are  applicable,  but  the  use  of  the  straight-edge  has  to  be 
dispensed  with. 

INTEEIOK  PLASTEEING. 

389.  The  signification  of  the  term  plastering  will  be  limited 
to  the  covering  of  interior  walls  and  ceilings,    interior  plaster- 
Exterior  plastering  will  be  denominated  "stuc- 

CO,"  although  the  technical  signification  of  the  latter  term  is 

much  more  limited,  and  refers  to  a  mixture  of 

white  lime,  putty,  and  white  sand  or  powdered 

marble,  used  for  inside  finishing,  and  to  a  coating  made  with 

this  compound. 

390.  Among  the  implements  used  by  the  plasterer,  the  prin- 
cipal ones  are  the  hawk,  the  plastering  or  lay-    ^  ^ 

ing-on  trowel,  the  fioat,  and  straight-edges  of 
various  lengths. 

391.  The  hawk,  used  by  the  plasterer  for  conveying  and 
holding  the  mortar,  while  he  applies  it  with  the 

trowel,  is  a  piece  of  board  about  eleven  inches 
square,  and  is  held  by  a  handle  fixed  beneath  in  the  centre  of, 
and  at  right  angles  to  the  board. 
14 


1 


210  PEACTICAL  TREATISE  ON  LIMES, 

392.  The  trowel  for  laying  the  mortar  consists  of  a  steel 
blade  about  3  inches  by  9  inches,  rounded  slight- 

Trowslt 

ly  at  the  front  end,  and  a  little  convex  on  the 
face,  with  a  wooden  handle  on  the  back  parallel  to  the  blade. 

393.  The  hand-float  is  of  wood,  similar  in 

shape  to  the  trowel,  and  is  used  to  rub  down 
the  finished  work  and  make  it  solid,  smooth,  and  even.  A  cork 
float  is  used  upon  surfaces  that  are  to  receive  a  high  degree  of 
polish  with  the  trowel. 

394.  The  mortars  used  for  inside  plastering  exclusively,  are 
Mortars  used  for  " coarse  stuff,"  "fine  stuff,"  "gauge  stuff,"  or 
plastering.  hard-finish,  and  "stucco." 

395.  Coarse  stuff  is  nothing  more  than  common  lime  mor- 

tar, suitable  for  brick  masonry,  to  which  has 
Coarse  stuff.  ,  ^  ^   ^  .        ^       iV     •    i    -.   i  i 

been  added  a  quantity  oi  well-switched  bul- 
lock's hair,  to  act  as  a  kind  of  bond.  The  following  proportion 
is  a  good  one : 

1  cask  lime  =  8  cubic  feet  of  paste. 
Sand  16  to  18  cubic  feet. 

Hair  1^   do.  do. 

396.  When  ample  time  for  hardening  cannot  conveniently 

be  allowed,  it  will  be  advantageous  to  replace  12  to  15  per 

cent,  of  the  lime  paste  in  the  coarse  stuff,  by  an  equal  volume 

of  the  paste  of  hydraulic  cement  or  plaster  of 
Its  uses.  X  ./  1 

Paris.    Coarse  stuff  forms  the  principal  part  of 

all  inside  plastering.    For  the  second  coat,  in  three-coat  work, 

the  quantity  of  hair  given  above  may  be  slightly  diminished. 

397.  Fine  stuff  is  made  of  pure  lump-lime  slaked  to  paste 

with  a  moderate  quantity  of  water,  and  after- 
Fine  stuff.  -. 

wards  diluted  with  water  to  the  consistency  of 

cream,  and  then  placed  where  it  can  stiffen  by  evaporation  to 

the  proper  condition  for  working. 

398.  Fine  stuff  is  used  for  the  finishing  coat,  but  never  with- 

out the  addition  of  sand  or  plaster  of  Paris,  ex- 
its uses.  .  . 

cept  for  what  is  termed  a  "  slipped  coat." 


HTDEAULIC  CEMENTS,  AND  MORTAES. 


211 


Even  for  slipped  work,  a  little  fine  sand  is  sometimes  added,  to 
make  the  paste  work  more  freely. 

399.  Gauge,  stvff,  or  hard-Jmish^  is  composed  of  fine  stuff 
(lime  pntty)  and  plaster  of  Paris,  in  proportions 

regulated  by  the  degree  of  rapidity  required  in  ^ard^fiiJsh^' 
hardening.  As  it  sets  rapidly,  it  is  always  pre- 
pared in  small  quantities  at  a  time,  not  more,  for  instance, 
than  can  be  used  up  in  half  a^i  hour.  It  is  used  for  the  finish- 
ing coat  of  walls,  and  for  cornices,  mouldings,  and  other  kinds 
of  ornamentation.  For  finishing,  the  proportions  are  three  to 
four  volumes  of  lime  putty  to  one  volume  of  plaster  of  Paris, 
and  for  cornices,  &c.,  about  equal  volumes  of  each. 

400.  Stucco  is  composed  of  lime  putty  and  white  sand,  with . 
a  preponderance  of  the  latter.    The  usual  pro- 

portions  are  three  to  four  volumes  of  sand  for 
one  volume  of  putty. 

Its  uses. 

Stucco  is  only  used  for  the  finishing  coat. 

401.  According  to  the  English  plasterer's  nomenclature,  ap- 
plying the  first  coat,  which  is  always  done  with 

coarse  stuff,  is  technically  termed  "  rendering,"  TomSiclature. 
if  on  masonry  ;  "  laying,"  if  on  laths  in  one  or 
two  coat  work;  and  "pricking  up,"  if  on  laths  in  three-coat 
work.  In  the  United  States,  the  first  coat  of  three-coat  work 
on  laths  is  called  the  "  scratch"  coat,  instead  of  the  "  pricked 
up"  coat.  The  other  terms,  with  the  English  signification,  are 
retained  here. 

402.  In  "  rendering,"  the  joints  of  the  masonry  should  be 
raked  out  to  the  depth  of  half  an  inch,  the  sur- 
face freed  of  dust,  and  the  walls  moistened.    Precautions  in 
Old  masonry,  if  smoky  or  greasy,  should  also  rendering. 

be  scraped  out  and  roughened. 

403.  One-coat  work, — Plastering  in  one  coat  without  finish, 

either  on  masonry  or  laths,  that  is,  either  ren- 

...  One-coat  work. 

dered  or  laid^  though  the  most  inferior  kind  of 

covering  for  walls,  is  frequently  used  for  attics  and  kitchens  in 


212 


PEACTICAL  TEEATISE  ON  LIMES, 


f  ^  ^  ^  cheap  houses,  and  for  cellars,  vaults,  and  places 
of  like  character.  The  coarse  stuff  is  applied 
in  the  same  manner  as  the  first  coat  in  two-coat  work,  described 
below.  A  light  hand-floating  is  of  great  advantage  to  this 
kind  of  work. 

404.  Two-coat  work. — Plastering  in  two  coats  is  done  either 

in  a  "  laying  coat  and        or  in  a  "  screed  coat 

and  The  screed  coat  is  also  called  the 

floated  coat.  It  is  more  commonly  applied  as  the  second  coat 
in  three-coat  work.  Laying  the  first  coat  in  two-coat  work,  is 
resorted  to  in  common  work  instead  of  scr ceding^  when  the 
finished  surface  is  not  required  to  be  exactly  even,  to  a  straight- 
edge. It  is  performed  in  a  pretty  thick  coat, — say  half  an 
inch, — more  care  being  taken  to  secure  a  smooth  and  even  sur- 
face than  in  the  scratch  coat  for  three-coat  work,  because,  in  the 
latter  case,  all  the  irregularities  are  removed  by  the  screed  coat 

which  follows.  In  both  the  laying  and  the 
wertempered       ^c^^*^^  ^0^*^'  the  coarse  stuff  should  be  well 

tempered,  and  of  such  moderate  consistency, 
that  when  pressed  with  force  against  the  laths,  it  will  penetrate 
between  them,  and  bend  down  over  them  on  the  inside,  so  as 

to  form  a  good  key.  A  common  fault  in  lath- 
latSng^  ^"S'  ^®  t^  place  the  laths  so  close  together,  as  to 

render  it  impossible  to  obtain  a  strong  key. 

405.  Except  for  very  common  work,  the  laying  coat  should 
be  hand-floated^  to  give  it  density  and  solidity.    This  is  done 

by  usins:  the  float  in  the  ris^ht  hand,  and  a  hair 
Hand-floating.  .  ^5 

brush  holding  water,  in  the  left ;  both  instru- 
ments passed  quickly  over  the  wall  at  the  same  time,  the  brush 
preceding  the  float,  and  wetting  the  surface  to  the  required 
degree.  The  firmness  and  tenacity  of  plastering  is  very  consid- 
erably increased,  by  hand-floating,  and  at  a  moderate  expense. 

406.  Hand-floating  must  take  place  while 
Must  take  place  .  ° 

while  the  mortar  the  mortar  IS  green,  when  it  is  intended  as  a 
ifi  green.  preparation  for  the  setting  coat. 


HTDKAULIC  CEMENTS,  AND  MOETAES. 


213 


407.  In  two-coat  work,  performed  in  a  screed  coat  and  set^ 
tli-e  first  coat  must  be  put  on  in  "  screeds"  and  "  filling  out." 
The  screeds  are  strips  of  mortar  six  to  eight  inch- 
es in  width,  and  of  the  required  thickness  of  the  described 

first  coat,  applied  at  the  angles  of  the  room, 
and  parallelly,  at  intervals  of  three  to  five  feet,  all  over  the 
surface  to  be  covered.    These  screeds  are  carefully  worked  on, 
so  as  to  be  accurately  in  the  same  plane,  by  the  frequent  appli- 
cation of  the  straight-edge  in  all  possible  directions.  When 
these  have  become  sufficiently  hard  to  resist  the  pressure  of  the 
straight-edge,  the  "  filling  out"  of  the  interspaces  flush  with 
the  surface  of  the  screeds  takes  place,  so  as  to 
produce  a  continuous,  straight,  and  even  sur-    The  screed  coat  to 
face.    The  surface  should  then  be  hand-floated 
as  described  above. 

408.  After  the  first  coat,  whether  it  be  a  laying  coat  or  a  screed 
coat,  has  become  partially  dry,  so  as  to  resist  the  pressure  of 
the  trow^el,  it  is  ready  for  the  setting,  or  finish- 
ing coat.    This  may  be  either  in  slipped  work^  Finishing. 
stucco^  hastard  stucco^  or  hard-finish.    In  all 

cases,  the  surface  to  receive  it  must  be  roughed  up  with  a  birch 
or  hickory  broom,  or  some  suitable  instrument,  and  if  too  dry, 
must  be  moistened. 

409.  A  slipped  coat  is  merely  a  smoothing  ofi*  of  a  browii 
coat  (coarse  stuif ) ,  with  the  smallest  quantity  of  lime  putty 
that  will  answer  to  secure  a  comparatively  even 

surface.    It  is  seldom  sufficient  to  cover  the  filJ^^^i^^^ 
browning  up  entirely. 

410.  A  small  quantity  of  white  sand,  seldom    Sand  sometimes 

.  .  Ill     us^d  in  the  sUpped 

exceedmg  three  per  cent.,  is  sometimes  addea    coat,  when  shp- 

to  the  putty  to  make  it  work  more  freely.    The  ^^rtTtt 
trowel  alone  is  used  for  this  kind  of  finish.  It 
answers  very  well  for  surfaces  that  are  to  be  finished  in  distem- 
per, or  with  paper-hangings  of  common  or  medium  quality. 

411.  Finishing  or  setting  in  stucco  is  suitable  for  a  screed 


214 


PEACTICAL  TEEATISE  Oii  LIMES, 


Stucco  flntshiug:  coat,  but  is  never  applied  to  laying  or  to  inferior 
work,  on  account  of  the  extra  labor  which  it 
Applied  with  requires.  The  stucco  is  applied  with  the 
trowel,  to  the  thickness  of  about  one-eighth  of 
an  inch,  keeping  in  view  the  fact  that  the  straight  surface 
gained  by  screeding  can  only  be  preserved  by  applying  the  set  in 
^  ,  ,    ,  a  coat  of  uniform  thickness.    The  stucco  is  well 

To  be  hand- 
floated,  hand-floated,  the  water-brush  being  used  freely 

while  so  doing.  After  the  wooden  float  has  been  used,  the 
surface  is  again  floated  in  the  same  manner  with  the  cork  float, 
which  being  soft,  leaves  the  surface  in  good  condition  for  polish- 
PoHshing  ^^^*    '^^^  polishing  is  performed  with  the  trowel 

and  brush;  this  operation,  however,  is  omitted, 
when  the  stucco  is  intended  to  present  a  rough  appearance  for 
painting,  or  for  any  style  of  ornamentation  in  distemper. 

412.  bastard  stucco,  like  stucco,  is  also  used 

Bastard  stucco  .  i         i       r    •     i  • 

as  a  settmg  coat  on  screed  work.  It  is  done  in 
stucco  mortar,  containing  a  smaller  quantity  of  sand  than  is 
Done  m  stucco      suitable  for  genuine  stucco,  and  sometimes  a 

mortar  with  a  rj^^^^.^  -g       haud-floatiug  in  thig 

diminished  dose         ^  ^       ^  ^ 

of  sand.  kind  of  work,  and  the  trowelling  is  done  witL 

less  labor  than  that  conferred  on  trowelled  stucco,  as  above 

Is  superior  to       described.    Bastard  stucco  is  superior  to  slipped 

shpped  work.        work  as  a  preparation  for  papering. 

413.  Rard-finuli  is  applied  with  the  trowel. 

Hard-finish.  iti/^t  •itp       -     t  t 

to  the  depth  oi  about  one-eighth  oi  an  inch.  It 
may  be  polished  with  the  water-brush  and  trowel,  but  the  hand- 
float  cannot  be  used  upon  it.    Hard-finished  walls,  though  fre- 
quently painted,  are  by  no  means  so  well  adapt- 
hand-floated  ^^^^  '^\Vi^  of  covering  as  stuccoed  walls. 

They  may,  however,  be  well  finished  in  distem- 
per; a  suitable  composition  for  this  purpose  consists  of  ten 
May  be  well  pounds  of  Paris  white  and  one  pound  of  glue, 
finished  in  colored  as  required.    The  advantage  of  hard- 

distemper,  finish  over  stucco  consists  in  its  requiring  less 


HYDEAULIO  CEMENTS,  AND  MOBTAES. 


215 


Three-coat  work. 


Scratch,  coat. 


labor  to  apply  it.  It  is  extensively  practised  in  the  United 
States. 

414.  Three-coat  worh. — The  first  and  second  coat  are  termed 
respectively  the  scratch  coat  and  hrown  coat,  and 
the  third  is  either  hard-finish^  or  stucco. 

415.  The  scratch  coat,  or  first  coat,  is  applied  in  the  same 
manner  as  laying^  with  this  exception,  that,  as  it 
is  simply  intended  to  form  a  good  foundation  for 
the  screeding  which  follows,  its  thickness  need  not  exceed  one- 
quarter  to  three-eighths  of  an  inch.  When  completed,  and 
partially  dry,  though  still  quite  soft,  the  mortar  is  scratched 
over  nearly  to  its  entire  depth,  with  a  pointed  stick,  in  two 
systems  of  parallel  scorings  at  right  angles  to  each  other,  run- 
ning diagonally  between  the  extreme  limits  of  the  surface  cov- 
ered. These  scorings  are  about  two  inches  apart,  and  assist 
the  adhesion  of  the  coat  which  follows. 

416.  The  second  coat  is  applied  in  "  screeds"  and  "  filling 
out,"  in  all  respects  as  described  in  screed-coat  and  set  work. 

417.  The  finishing  or  setting  is  also  applied  as  before  de- 
scribed 

418.  Table  XY.  gives  an  estimate  of  labor  and  materials  for 
100  yards  of  lath  and  plaster  w^ork  : 

TAELE  XV. 


Materials. 


Rockland  lime  

Lump  lime  for  fine  stuff. 

Plaster  of  Paris  

Laths  

Hair  

Common  sand  

White  "   

Nails  

Mason's  labor  

Laborer  

Cartage  


Cost  of  100  yards  $25.50 


Three  coats 
Hard-finished  work. 


4  casks. 


2,000   

4  bushels.  . 

7  loads  

bushels. 

13  lbs  

4  days  


$4.00 
.85 
.10 
4.00 
.80 
2.00 
.25 
.90 
1.00 
3.00 
2.00 


Two  coats 
Slipped  work. 


3^  casks , 


2,000  

3  bushels. 
6  loads. . . 


13  lbs. . 
'i^  days. 


$3.33 


4.00 
.60 
L80 


.90 
6.12 
2.00 
1.20 


216 


PEACTICAL  TREATISE  ON  LIMES, 


EXTEEIOR  PLASTEEma,  OR  "  STUCCO." 

419.  Mortars  composed  of  the  paste  of  common  lime  and 

sand,  either  with  or  without  the  addition  of 
uStfo? outsSr  P^^^*^^  Paris,  are  unsuitable  for  covering 
work.  surfaces  exposed  to  the  direct  action  of  the  ele- 

ments. 

420.  Lime,  Lowever,  forms  the  basis  of  many  excellent  out- 
side stuccos,  and,  by  proper  treatment,  may  be  rendered  very 
durable. 

421.  If  the  water  for  mixing  the  mortar  contains  coarse  sugar 

or  molasses  in  solution,  the  effect  on  the  solidifi- 
water  ^  cation  of  the  outer  surface  of  the  stucco  is  very 

beneficial.  This  method  is  practised  by  the 
natives  of  India,  as  reported  by  Captain  Smith  in  his  transla- 
tion of  Yicat.  The  proportions  for  the  sweetened  water  are 
about  one  pound  of  sugar  to  eight  gallons  of  water,  except 
for  the  outer  or  hand-floated  coat,  in  which  one  pound  of  sugar 
should  be  mixed  with  two  gallons  of  water. 

422.  Powdered  slaked  lime  and  smith's  forge  scales  mixed 

up  with  bullock's  blood  in  suitable  proportions, 
scales  ^  ^^^^^         make  a  durable  and  moderately  hydraulic  mor- 
tar, which  adheres  well  to  masonry  previously 
coated  over  with  boiled  oil.    It  is  used  for  outside  stucco. 

423.  The  custom  in  the  United  States  is  to  use  hydraulic 

cement  and  clean  sand,  mixed  up  with  a  sufli- 
SS^r^"" ciency  of  water  to  produce  the  ordinary  consist- 
ency of  mortar  for  plastering,  and  in  such  quan- 
tities that  all  may  be  used  up  before  the  batch  begins  to  set.  The 
proportions  are  one  volume  of  stiff  cement  paste  to  1.66  vol 
umes  of  damp,  compact  sand ;  or,  if  measured  dry,  one  volumo 
of  cement  powder  to  two  volumes  of  loose,  dry  sand. 

424.  "When  masonry,  either  of  brick  or  stone,  is  to  be  stut 
^  ^  .  coed,  the  joints  should  be  raked  out  to  the  depth 
same.                of  half  an  inch ;  the  surface  cleansed  of  dirt  and 


HYDEAULIC  CEMExNTS,  AND  MORTARS. 


217 


dust,  and  tlien  thoroughly  wetted,  (with  a  hose,  if  possi- 
ble,) so  that  the  mortar  will  not  be  too  rapidly  deprived 
Df  its  moisture  by  absorption,  and  its  strength  and  density 
thereby  impaired.  If  the  surface  is  greasy,  it  should  be  scored 
with  an  axe. 

425.  The  mortar  is  applied  in  two  coats  laid  on  in  one  oper- 
ation.   That  for  the  first  coat  should  be  some-        ^     ^  „ 

First  coat  of 

what  thinner  than  that  for  the  second,  in  order    rather  thin 

that  it  may  be  pressed  into  thorough  contact 

with  the  wall,  and  enter  and  fill  up  all  the  joints  and  other 

openino^s.    The  second  coat  is  applied  upon  the 

^  1  .1      1      1  .  n  f       1       Second  coat. 

first,  while  the  latter  is  yet  soit,  so  that  the 

same  workman  finishes  ofi"  as  he  goes  along,  never  covering 

more  than  two  or  three  superficial  feet  at  one  time.    The  two 

eoats  thus  laid  should  form  one  compact  coat,  of  about  one-half 

inch  in  thickness.    The  finished  stucco  should 

be  kept  shaded  from  the  direct  rays  of  the  sun    ^^^^  protected 

for  some  days,  and  moistened  from  time  to    f'^^^  sun,  and 

'  kept  moist. 

time. 

426.  As  a  modification  of  the  above  process,  the  first  coat  is 
sometimes  omitted,  or  rather  replaced  by  a  wash 

of  thick  cream  of  pure  cement,  applied  with  a  Slve^process.^ 
stiff  brush,  from  time  to  time,  just  before  the 
mortar  is  put  on.    If  the  brush-work  is  faithfully  done,  and  not 
allowed  to  dry  before  the  surface  receives  the  stucco,  an  inti- 
mate contact  and  firm  adhesion  are  sure  to  result. 

427.  A  necessary  precaution  in  this  kind  of  work  is  to  secure 
the  services  of  a  faithful  workman,  one  who  will 

Precaution. 

not  spare  his  strength,  or  Jay  any  oi  the  mortar 
on  too  loosely,  or  on  too  dry  a  surface ;  otherwise,  there  will 
be  portions  without  adhesion,  that  will  be  thrown  off  on  the 
first  occurrence  of  frost. 

428.  After  the  stucco  has  been  on  for  a  few 

days,  the  whole  surface  should  be  carefully  Sltriortu^' 
Bounded  with  a  small  iron  instrument  like  a 


218 


PEACTICAL  TREATISE  ON  LIMES, 


tack-hammer,  when  all  places  destitute  of  adhesion  will  be 
readily  detected  by  their  hollow  sound.  From  these,  the 
stucco  should  be  carefully  removed,  the  surface  roughened  and 
wetted,  and  new  mortar  applied. 

429.  Many  of  the  best  cements  of  the  United 
^ion^^°^^^*         States  are  of  too  dark  a  color  to  furnish  an 

agreeable  shade  for  the  exterior  of  dwelling 
houses.  A  very  simple  remedy  for  this  is  to  use  light  colored  or 
white  sand,  in  whole  or  in  part.  When  this  is  not  practicable, 
lime  paste  may  be  added,  without  material  injury,  until  its 
volume  equals  that  of  the  cement  paste.  Lively  tints  may  be 
obtained  by  a  judicious  use  of  the  several  ochres,  singly  or 
combined. 

430.  The  principal  causes  of  the  gradual  de- 
SZarTiftheal    terioration  and  decay  of  mortars  left  in  the 

open  air  are : 

1st.  Ordinary  changes  of  temperature,  producing  expansions 
and  contractions,  which,  being  unequal  in  the 
several  materials  ordinarily  used  in  masonry, 
tend  to  cause  a  separation  of  the  mortar  from  the  more  solid 
parts. 

2d.  Alternations  of  freezing  and  thawing,  by 
2d  cause.  which  exfoliations  and  disintegrations  are  pro- 

duced. 

431.  As  a  p-eneral  fact,  within  certain  limits. 
General  fact.  .         r.  ^  . 

solid  bodies  resist  the  action  oi  irost  m  propor- 
tion to  their  density,  or  inversely  as  their  capacity  for  imbibing 
water  ;  but  this  rule  is  not  capable  of  strict  application,  and  it 

is  quite  possible  for  one  mortar  to  be  a  better 

Some  mortars  «         -     .     n     .  . i  i 

resist  frost  better    pi'oot  against  irost  than  another  less  porous 

than  others  that  i^i  its  character.  Moreover,  of  two  mortars  of 
are  less  porous.  ' 

equal  density,  one  may  be  materially  impaired 

in  tenacity  and  hardness  by  the  action  of  frost,  while  the  other 

exhibits  few,  if  any,  evidences  of  its  effects. 

432.  Immersed  in  water,  more  especially  sea-water,  mortars 


HYDEAULIC  CEMEOTS,  AND  MOETARS. 


219 


are  subjected  to  the  solvent  action  of  the  salts   -^^^^^^  of  certain 
— principally  the  sulphates  of  magnesia  and    salts  in  sea- 
soda, — and  certain  gases  contained  in  the  water. 
Between  tides,  are  witnessed  the  effects  of  a  combination  of 
the  foregoing  causes,  modified  and  sometimes  augmented  by 
the  circumstance,  that  the  protecting  coat  of  marine  animals 
and  shells,  to  which  many  submarine  construc- 
tions in  a  measure  owe  their  stability,   is    be^tween  the  tides, 
seldom  found  at  all,  and  at  best,  but  very  im- 
perfectly, in  positions  not  subject  to  constant  submersion.  It 
is  hence,  not  an  uncommon  thing  to  see  the  mortar  of  that 
portion  of  a  structure  between  high  and  low  water,  in  a  more 
advanced  stage  of  decay  than  that  above  or  below. 

433.  The  effects  of  frost  on  mortar  may  be  ascertained  by 
subjecting  it  to  repeated  action  of  artificial  frigorific  mixtures. 
To  do  this,  the  mortar  should  be  four  or  five 
months  old,  and  in  the  form  of  a  prism  of  effects  of  fros*t^ 
suitable  size,  say  2"  X  2"  X  8".  Ascertain  the 
strength  before  the  freezing  trial,  by  breaking  the  prism, 
near  one  end,  on  supports  four  inches  apart.  Then  saturate 
the  largest  piece  with  water,  put  it  in  a  thin,  water-tight 
bag  of  India-rubber  or  gutta-percha  cloth,  and  immerse  it 
in  one  of  the  frigorific  mixtures  given  below,  where  it  should 
be  kept  until  the  temperature  of  the  mixture  rises  above  the 
freezing  point.  The  sample  should  then  be  laid  in  some  warm, 
dry  place,  until  it  is  completely  thawed  out.  After  eight  or 
ten  repetitions  of  this  process,  the  strength  of  the  mortar 
should  be  ascertained  as  in  the  first  instance,  when  the  effect 
of  frost  will  become  known. 


220 


PRACTICAL  TREATISE  ON  LIMES, 


TABLE  XYL 

FRIGORIFIC  MIXTURES. 


Mixtures. 

1  Parts.  1 

Thermometer 
sinks. 

Mixtures. 

1  Parts.  1 

Thermometer 
sinks. 

Snow  or  pounded  ice 

2 
1 

1  From  any  temperature 

-to- 5°  F. 

Snow  or  pounded  ice . . 

5 
2 
1 

0  ^ 

1  tto-12<'F. 
^  ) 

Snow  or  pounded  ice 
Common  salt  

24 
10 
5 
5 

^to-18°  F. 

Snow  or  pounded  ice.. 
Common  salt  

12 

5 
5 

3  ■ 
1) 

1  Vto-25oF. 

Nitrate  of  potash  . .  . 

Nitrate  of  ammonia  . . . 

434.  The  process  of  a  French  chemist,  M.  Brard,  for  esti- 
M.  Brard's  pro-  mating  the  probable  effects  of  frost  on  stone, 
cess.  given  in  the  "Annales  de  Chimie  et  de  Physi- 
que," volume  38,  is  equally  applicable  to  mortar.  It  may  be 
stated  very  briefly  as  follows,  viz.  :  Prepare  a  cold  saturated 
solution  of  sulphate  of  soda,  then  bring  it  to  the  boiling  point, 
and  suspend  in  it,  by  a  string,  for  thirty  minutes,  the  sample 
under  trial.  Then  pour  the  liquid,  free  of  sediment,  into  a 
flat  vessel,  and  suspend  the  stone  over  it  in  a  cellar.  When 
efliorescences  appear  on  the  specimen,  it  must  be  dipped  in  the 
solution,  say  two  or  three  times  a  day  for  about  a  week  ;  at  the 
end  of  which  time  the  quantity  of  earthy  sediment  in  the  ves- 
sel, collected  on  a  filter  and  weighed,  will  indicate  the  effect 
to  be  expected  from  frost  on  the  same  sample.  The  sample 
under  trial  might  also  be  of  such  a  form,  that  its  strength  could 
be  tested  before  and  after  subjection  to  the  above  process.  M. 
Brard,  however,  makes  no  recommendation  of  the  kind,  and 
it  is  perhaps  unadvisable  when  operating  upon  stone. 

435.  The  subject  of  the  action  of  sea- water  on  mortars,  par- 
Effect  of  the  sea-  ticularly  the  pozzuolana  mortaa's  used  in  the 
water  on  mortars.  Mediterranean  Sea,  and  the  conflict  of  opinion 
thereon  among  European  engineers,  has  been  referred  to  in 
brief  terms  in  Chapter  lY.  To  estimate  by  preliminary  ex- 
periments the  probable  effects  of  sea-water  on  mortars,  in  any 


HYDRAULIC  CEMENTS,  AND  M0RTAH8. 


221 


given  case,  is  a  difficult  thing :  in  fact,  there  are  so  many  ele- 
ments of  uncertainty  involved  in  it,  that  many  engineers  deem 
it  impossible.  ^Nevertheless,  M.  Yicat  proposed  in  1857  "a 
new  mode  of  tryins;  sea-mortars  in  the  labora-    ,^  ^, 

_®  ^  M.  Vicat's  new 

tory,"  which,  as  it  emanates  from   high  au-    method  of  testing 

thority,  is  entitled  to  notice.    The  mortar  to  be 

tried,  when  mixed  up,  is  pressed,  while  green,  into  an  earthen 

vessel.    The  vessel  should  be  full  and  should  be  kept  closely 

covered,  to  prevent  contact  with  the  air.    At  the  expiration 

of  one  month  break  the  vessel,  so  as  to  free  the 

T    ,1        .  ^  j^i.      •  i        Immerse  the  mor- 

mortar,  and  then  immerse  the  latter  m  water  ^g^^  ^  solution 
containing:  four  or  five  thousandths  of  anhy-    of  anhydrous  sui- 

c>  phate  of  magnesia 

drous  sulphate  of  magnesia.    Reaction  takes 
place,— 'the  water  dissolves  the  sulphate  of  lime  formed,  its 
presence  being  detected  by  oxalate  of  ammonia,  which  yields 
a  precipitate  of  oxalate  of  lime. 

436.  The  solution  of  sulphate  of  magnesia  should  be  re- 
newed until  no  more  of  this  oxalate  is  formed,    Renew  the  so- 
and  even  beyond  that  point,  for  greater  cer-  lution. 
tainty. 

437.  If  the  sample  shows  no  external  signs  of  decay  after 
ten  months,  break  it  open  and  examine  the  frac-  Examination  of 
ture.  If  the  interior  is  in  a  state  of  perfect  pres-  specimen, 
ervation,  treat  some  fragments,  taken  from  the  inside,  by  the 
game  process  applied  to  the  original  sample.  If  these  frag- 
ments remain  intact,  for  a  given  time,  (yet  to  he  ascertained)  the 
mortar  may  be  pronounced  suitable  for  sea  constructions.  For 
cement  mortars,  twenty  months'  successful  resistance  to  the 
solution  of  sulphate  of  magnesia  is  considered  ample  by  M. 
Yicat.  For  mortars  of  pozzuolana  or  hydraulic  lime,  it  is  not 
considered  entirely  safe  to  assign  a  minimum  of  two  years  ; 
while  it  is  by  no  means  impossible  for  a  mortar  that  fails  to 
stand  this  test  to  sustain  immersion  in  the  sea,  from  the  fact 
that  the  protecting  coat,  before  referred  to,  is  formed  on  the 
exposed  surface. 


PRACTICAL  TREATISE  ON  LIMES, 


438.  M.  Minard,  Engineer  des  Fonts  et  Chaussees,  (retired,) 
concludes  a  review  of  M.  Yi cat's  work  in  the 
Jliin^on!'''^''  Annales  des  Fonts  et  Chaussees"  for  1858,  as 

follows : 

"  The  only  means  of  knowing  the  action  of  the  sea  on  a  new 
mortar  is  to  immerse  it  in  the  sea,  in  the  locality  where  it  is  to 
be  used.  Substituting  chemical  operations  in  laboratories  for 
the  sea  itself,  involves  us  in  new  disasters." 


HYDKAULIO  CEMEOTS,  AND  MOETAES.  223 


CHAPTEK  YII. 

A'M.  ^Jf^i  Crete  or  Beton. — These  terms,  by  no  means  origin- 
sj/ionymous,  have  become  almost  strictly  so  by  usage. 
As  generally  understood  in  modern  practice,  they  apply  to  any 
mixture  of  mortar  (generally  hydraulic),  with  coarse  materials, 
such  as  gravel,  pebbles,  shells,  or  fragments  of  Definition  of  terms 
tile,  brick,  or  stone.  Two  or  more  of  these  mate-  "  concrete"  and 
rials,  or  even  all  of  them,  may  be  used  together. 
More  strictly  speaking,  as  originally  accepted,  the  matrix  or 
gang  of  heton  possesses  hydraulic  energy,  while  that  of  concrete 
does  not. 

440.  As  lime  or  cement  paste  is  the  cementing  substance  in 
mortar,  so  mortar  itself  occupies  a  similar  relation  to  concrete 
or  beton.    Its  proportion  should  be  determined  in  accordance 
with  the  principle,  that  the  volume  of  the  cement-    y^q^q^<^-^q^  of 
ing  substance  should  always  he  somewhat  in  ex-    matrix  to  the 

„    ,        ,  ...  coarse  materials. 

cess  of  the  volume  of  voids  m  the  coarse  mate- 
rials to  he  united.    The  excess  is  added  as  a  precaution  against 
imperfect  manipulation. 

441.  In  England,  some  years  ago,  when  concrete  first  came 
into  extensive  application,  common  or  feebly  hydraulic  lime, 
such  as  the  Blue  Lias  limestone  yields,  was  generally  used  for 
the  cementing  substance.  The  quicklime,  having  been  first 
reduced  to  a  powder  by  mechanical  means,  was  incorporated 
with  the  sand  and  coarse  materials  in  the  dry 

Btate.  Water,  in  sufficient  quantity  to  slake  Concrete  of  quick- 
the  lime,  being  then  added,  the  concrete  was 


224 


PRACTICAL  TREATISE  ON  LIMES, 


rapidly  mixed  up  with  a  png-mill  or  with  shovels,  conveyed 

away  in  barrows  or  carts,  and  used  while  hot. 
Used  while  hot.        ^  ^       ^  .     -,     ^       .  -, 

it  was  employed  extensively  for  loundations, 

or  as  a  substratum  in  light  and  yielding  soils.  In  order  to  se- 
cure the  requisite  degree  of  compression  and  density,  it  w^as 
customary  to  throw  it  into  its  position  from  a  height,  and  some- 
times to  ram  it  afterwards.  In  mixing  the  materials  for  fat 
Its  contraction  concrete  as  usually  composed,  there  is  a 

and  subsequent      contraction  of  about  "I  in  volume  ;  this  is  suc- 

expansion.  i    i  ,  •  i         i  •  ^ 

ceeded  by  an  expansion,  when  the  setting  takes 
place,  of  about  f  of  an  inch  for  every  foot  in  height,  which 
does  not  entirely  cease  for  a  month  or  two  afterwards. 

442.  Concrete  of  fat  or  feebly  hydraulic  lime  has  been  ex- 
tensively employed  in  Europe  for  making  artifi- 
S^uropf  "^^  ^^^^  ^^'^  blocks  of  any  required  form  and  dimensions, 
which,  after  attaining  in  the  air  a  degree  of  hard 
ness  and  strength  sufficient  to  render  the  handling  of  them  safe 
and  practicable,  are  laid  up  in  walls  with  mortar  joints,  like 
ashlar-work. 

The  practice  of  443.  Of  late  years,  the  practice  of  laying  fat 

crete^getting  into  ^^^'^^  Concrete  hot  has  grown  into  disrepute 
disrepute.  among  English  architects  and  engineers.  They 

now  prefer  that  the  lime  should  be  thoroughly  slaked,  reduced 
to  a  pulp,  and  made  into  mortar  with  the  sand  before  the  coarse 
materials  are  added.  This  process  is  always  followed  in 
making  beton.  The  advantages  of  it  are,  immunity  from 
the  danger  of  partial  slaking  before  use,  superior  homoge- 
neousness  in  the  mass,  and  economy  in  the  amount  of  lime 
required. 

444.  [N'either  the  English  method  of  making  concrete  to  be 
English  methods  ^^^^  while  hot,  nor  the  practice  of  forming  ar- 
httle  used  in  the  tificial  blocks  which  must  attain  in  the  air  a 
United  States.  ,      ,  r.       •  -  •  i.  j?  i.i 

certain  degree  oi  resisting  power  beiore  they 
can  be  placed  in  the  work  for  which  they  are  designed,  have 
ever  received  any  extensive  application  in  the  United  States. 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


225 


445.  Natural  hydraulic  cement,  to  which,  un-    Hydraulic  cement 
der  circumstances  requiring  only  a  moderate  the^united^^^ 
degree  of  energy  and  strength,  paste  of  fat  lime  States. 

is  sometimes  added,  in  quantities  seldom  greatly  exceeding  that 
of  the  cement,  is  almost  invariably  used  as  the  basis  of  the  con- 
crete mortar ;  and  the  concrete,  when  made,  is  at 
once  deposited  in  its  allotted  place,  and  well    General  practice, 
rammed  in  horizontal  layers  of  about  6  inches  in 
thickness,  until  all  the  coarser  fragments  are  driven  below  the 
general  surface.    The  ramming  should  take 
place  before  the  cement  begins  to  set,  and  care    ^Precautions  in 

^  ^  '  ramming,  and  m 

should  be  taken  to  avoid  the  use  of  too  much    the  use  of  water 

wa^er  in  the  manipulation.    The  mass,  when 

ready  for  use,  should  appear  quite  incoherent.    Concrete  should 

,   .   .  ^      ,  .  ,  .  .         be  incoherent  be- 

contammg  water,  however,  m  such  quantities,    fore  ramming, 
that  a  thorough  and  hard  ramming  will  produce 
a  thin  film  of  free  water  upon  the  surface,  under  the  rammer, 
without  causing  in  the  mass  a  gelatinous  or  quicksand  motion. 

446.  It  will  be  found  in  practice  that  cements  vary  very  consid- 
erably in  their  capacity  for  water,  and  that  fresh  ground  cements 
require  more  than  those  that  have  become  stale.  An  excess  of 
water  is,  however,  better  than  a  deficiency,  particularly  when  a 
very  energetic  cement  is  used,  as  the  capacity  of  this  substance 
for  solidifying  water  is  great.  A  too  rapid  desic- 
cation of  the  concrete  might  involve  a  loss  of  ^anTdefidencj 
cohesive  and  adhesive  strength,  if  insufficient  of  water, 
water  be  used. 

447.  Concrete  is  admirably  adapted  to  a  variety  of  most  im- 
portant purposes,  and  is  daily  growing  into  more  extensive  use 
and  application.  For  foundations  in  damp  and  yielding  soils, 
and  for  subterranean  and  submarine  masonry, 

under  almost  every  combination   of  circum-    ^^ges  of  "^concrete, 
stances  likely  to  occur  in  practice,  it  is  superior 
to  brick- work  in  strength,  durability,  and  economy ;  and  in  some 
exceptional  cases,  is  considered  a  reliable  substitute  for  the  be&t 
15  * 


226 


PRACTICAL  TREATISE  ON  LIMES, 


stone,  while  it  is  almost  always  preferable  to  the  poorer 
varieties. 

448.  For  submarine  masonry,  concrete  possesses  the  advan- 
Advantages  for  ^^g^j  ^^^t  it  may  be  laid  without  exhausting  the 
submarine  works,  water,  (which  under  the  most  favorable  circum- 
stances, is  an  expensive  operation,)  and  also  without  the  aid  of  a 
diving-bell,  or  submarine  armor.  On  account  of  its  continuity 
and  impermeability  to  water,  it  is  well  suited  to  the  purposes 
of  a  substratum  in  soils  infected  with  springs,  for  sewers  and 
conduits,  for  basement  and  sustaining  walls,  for  columns,  piers, 
and  abutments,  for  the  hearting  and  backing  of  walls  faced  with 
bricks,  rubble,  and  ashlar-work,  for  pavements  in  areas,  base- 
ments, and  cellars ;  for  the  walls  and  floors  of  cisterns,  vaults, 
&c.  Groined  and  vaulted  arches,  and  even  entire  bridges, 
dwelling-houses,  and  factories,  in  single  monolithic  masses,  with 
moulded  ornamentation  of  no  mean  character,  have  been  con- 
structed of  this  material  alone. 

449.  The  methods  pursued  in  mixing  mortar  on  the  fortifica- 
tions of  Boston  and  New  York  harbors,  and  at  Key  West, 
Florida,  have  been  described  in  brief  and  general  terms  in 
Chapter  YI.,  paragraph  346  and  following.  The  manner  of 
incorporating  the  broken  stone  fragments,  as  practised  on  the 
works  at  New  York,  is  also  briefly  alluded  to  in  the  7th,  8th, 
9th,  and  10th  steps  in  the  method  of  manipulation,  paragraphs 
373,  374,  and  375.  When  the  coarse  fragments  vary  very 
much  in  their  sizes,  and  these  have  been  separated  by  a 
screen,  as  may  be  the  case  with  gravel  and  pebbles  collected 
in  the  usual  way,  a  more  thorough  incorporation  may  per- 
haps be  secured  by  spreading  them  first  on  the  platform  with 
the  smallest  sizes  at  the  bottom,  and  then  distributing  the 
mortar  uniformly  over  the  mass.  This  process  was  followed 
in  Boston,  and  is  thus  described  by  Lieutenant  Wright,  in  his 
work  on  mortars  : 

450.  "  The  concrete  was  prepared  by  first  spreading  out  the 
gravel  on  a  platform  of  rough  boards,  in  a  layer  from  eight  to 


HYDEAULIC  CEMENTS,  AIS^D  MORTAES.  227 


twelve  inches  thick,  the  smaller  pebbles  at  the 

Incorporating  the 

bottom  and  the  larger  on  the  top,  and  after-    coarse  ingredi- 

,  J.       ,1  ,  'i?       1       ents  by  ha.nd. 

wards  spreading  the  mortar  over  it  as  uniiormly 

as  possible.  The  materials  were  then  mixed  by  four  men,  two 
with  shovels  and  two  with  hoes,  the  former  facing  each  other, 
and  always  working  from  the  outside  of  the  heap  to  the  centre, 
then  stepping  back  ;  and  recommencing  in  the  same  way,  and 
thus  continuing  the  operation  until  the  whole  mass  was  turned. 
The  men  with  hoes  worked,  each  in  conjunction  with  a  shov- 
eller, and  were  required  to  Txih  well  into  the  mortar^  each 
shovelful,  as  it  was  turned  and  spread,  or  ratker  scattered  on 
the  platform  by  a  jerking  motion.  The  heap  was  turned  over 
a  second  time  in  the  same  manner,  but  in  the  opposite  direc- 
tion, and  the  ingredients  were  thus  thoroughly  incorporated, 
the  surface  of  every  pebble  being  well  covered  with  mortar. 
Two  turnings  usually  sufficed  to  make  the  mixture  complete, 
and  the  resulting  mass  of  concrete  was  then  ready  for  transpor- 
tation to  the  foundation. 

"  The  success  of  the  operation,  however,  depends  entirely 
upon  the  proper  management  of  the  hoe  and  shovel,  and  though 
this  may  be  easily  learned  by  the  laborer,  yet  he  seldom  ac- 
quires it  without  the  particular  attention  of  the  overseer. "^"^ 

451.  In  Europe,  machinery  is  sometimes  employed  for  incor- 
porating the  ingredients  of  concrete,  when  large  quantities  are 
required. 

452.  The  concrete  for  the  bridge  over  the  River  Theiss,  Hun- 
gary, completed  in  the  year  1857,  was  prepared  with  a  machine 
extensively  used  in  Germany  at  that  time.  It  consists  of  a 
cylinder  about  four  metres  (13  feet)  in  length. 

Machine  used  in 

and  1.25  metres  (four  feet)  m  diameter,  open  at  Hungary  for  mix- 
both  of  its  extremities  and  revolving  fifteen  to  '""^  concrete, 
twenty  times  per  minute  around  its  axis,  which  is  inclined  to 
the  horizon  at  an  angle  of  six  to  eight  degrees.  The  stone  and 
mortar  are  thrown  from  the  wheel-barrow  into  a  hopper,  which 
empties  them  into  the  upper  end  of  the  cylinder.    'Jhe  mixture 


228 


PRACTICAL  TREATISE  ON  LIMES, 


is  produced  by  the  rotation  of  the  cylinder,  from  the  lower  end 
of  which  the  concrete  drops  into  either  wheel-barrows  or  carts. 
Tlie  inner  surface  of  the  cylinder  is  smooth  and  coated  with 
sheet-iron  ;  the  proportion  of  the  material  is  measured  by  reg- 
ulating the  number  of  wheel-barrow  loads  of  mortar  and  oi 
stone,  as  these  are  poured  into  the  hopper.  The  incorporation 
of  the  ingredients  is  complete.  The  cylinder  is  kept  in  motion 
without  cog-wheels  or  pulleys,  simply  by  means  of  a  leather 
strap  which  passes  over  its  exterior  surface  ;  the  motive  power 
was  furnished  by  a  locomotive,  which  worked  a  heavy  mortar- 
mill  at  the  same  time. 

This  machine  easily  mixes  from  80  to  100  cubic  metres 
(105  to  130  cubic  yards),  in  ten  hours,  and  (when  worked  in 
connection  with  a  mortar-mill)  at  a  trifling  expense.  (See 
Annates  des  Fonts  et  Chaussees^  Vol.  XYII.,  1859.) 

453.  Another  machine  for  making  concrete,  the  mortar  hav 
ing  been  previously  mixed,  is  represented  by  Figures  40,  41^ 
42,  43,  and  44,  the  latter  being  a  top  view.  It  is  always  used 
in  a  vertical  position,  and  being  comparatively  light  and  port- 
able, and  worked  altogether  by  hand,  possesses  the  advantage 
that,  for  founding  in  dry  positions,  or  where  the  water  has  been 
exhausted,  it  can  be  suspended  with  its  lower  end  resting  on 
„  , .    ^      .      the  position  to  be  occupied  by  the  concrete,  and 

Machine  for  tcxsl-  ^  ^  . 

ing  concrete         one  handling  of  the  materials  be  thereby  saved. 

worked  by  hand.       A«i^'  i  '     i  jy 

As  it  IS  moved  successively  irom  one  position 
to  another,  during  the  progress  of  the  work,  it  is  followed  up 
by  laborers  who  level  off  and  ram  the  concrete  already  de- 
posited by  it.  In  using  this  machine,  the  mortar  and  coarse 
materials,  after  having  been  measured,  are  placed  in  the  top 
compartment,  Fig.  40.  The  levers,  hh^  Fig.  44,  being  then 
put  in  motion,  the  materials  fall  successively  from  one  compart- 
ment to  another,  little  by  little,  and  finally  reach  the  bottom 
thoroughly  and  completely  mixed.  As  the  top  compartment 
becomes  empty,  the  ingredients  for  another  batch  of  concrete 
are  placed  in  it. 


HYDEAULIC  CEMEXTS,   AND  MORTARS. 


229 


r 

0 

u 

Fig.  40. 


Fio:.  43. 


Fig.  44. 


454.  Wheel-barrows  are  generally  used  for  conveying  the 

concrete  from  the  platform  on  which  it  is 

...  1       mi       1  Wheel-barrows 

mixed,  to  its  position  m  the  work,    ihe  plat-     for  conveying 

form  should  be  so  arranged,  if  possible,  that  concrete. 

':he  distance  to  be  passed  over  will  not  exceed  twenty  or  twen- 


230 


PEAOTICAL  TEEATISE  ON  LIMES, 


tj-five  yards.  The  concrete  having  been  emptied  from  the 
barrows  into  its  position,  is  levelled  off  with  a  hoe,  and  rammed 
in  layers  six  to  ten  inches  in  thickness. 

455.  The  instrument  used  for  ramming  concrete  is  generally 
a  cylinder  of  w^ood  six  to  eight  inches  in  diameter,  and  about 
eight  inches  high,  shod  with  sheet-iron  on  the  lower  end, 
and  having  a  handle,  three  to  three  and  a  half  feet  long,  in- 
serted in  the  other  end,  in  the  prolongation  of  the  axis.  For 
greater  convenience,  a  hand-piece  is  sometimes  attached  at  a 
suitable  height  on  the  handle. 

456.  When  concrete  is  made  by  a  machine,  particularly  one 
Sling-cart  for  con-  very  portable,  and  not  conveniently  kept  in 
veying  concrete.  ^losc  proximity  to  the  place  to  be  concreted,  a 
sling-cart,  like  that  described  in  paragraph  383,  would  be  a 
valuable  auxiliar  to  the  work.  The  box  slung  underneath  the 
cart,  could  be  replaced  by  a  platform  arranged  to  receive  a 
certain  number  of  square  boxes  of  convenient  size  for  handling 
when  filled.  With  a  view  to  economize  labor,  the  mill  should 
be  adjusted  so  as  to  discharge  the  manufactured  concrete  di- 
rectly into  the  boxes. 

457.  The  device  for  confining  the  concrete  layers  laterally, 

so  as  to  2:ive  to  the  finished  work  the  desired 

A  boxing  neces-  ^ 

sary  in  making       form,  will,  of  course,  to  a  certain  extent,  depend 

concrete  walls.  ,  -.         ...        ^  .i  i 

on  the  character  and  position  or  the  work,  ii 

required  for  foundations,  or  for  the  backing  of  walls,  or  in  any 

position  not  exposed  to  view,  or  not  requiring  a  smooth  finish, 

a  rough,  movable  boxing,  composed  of  two  or  more  planks, 

with  their  edges  together,  and  well  secured  by  battens  on  the 

back,  will  suffice. 

458.  When  it  is  required  to  give  a  smooth  finish  to  the  con- 
crete wall,  and  when  it  is  essential  that  the  direction  and  po- 
sition of  the  surfaces  should  be  maintained  with  great  accuracy, 
special  attention  should  be  directed  to  the  boxing. 

459.  A  device  by  Mr.  E.  E.  Clarke,  of  ISTew  Haven,  Conn., 
to  be  used  in  erecting  concrete  houses,  has  been  pronounced 


HYDEATJLIC  CEMENTS.  AISTD  MOETAKS. 


231 


both  convenient  and  satisfactory,  while  it  apparently  leaves 
nothing  to  be  desired  on  the  score  of  simplicity    improved  mov- 
and  economy.   It  consists  essentially  of  a  wood-    ^^1®  boxing. 

en  clamp,  the  vertical  parallel 
arms  of  which  can  readily  be 
adjusted  by  means  of  traverse 
screws,  to  any  required  thick- 
ness of  wall.  These  arms  sup- 
port the  planking  which  deter 
mines  the  thickness  of  the  wall, 
and  are  attached — one  fixed, 
and  the  other  movable — to  a 
horizontal  brace.  When  in  use^ 
the  entire  apparatus  is  kept 
in  position  by  securing  this 
brace  to  some  fixed  point  of  sup- 
port. In  carrying  up  the  walls 
of  a  building,  these  points  of 
support  are  provided  on  the  in- 
side, being  vertical  posts  secured 
to  the  ground,  in  the  first  in- 
stance by  braces,  and  afterward 
to  tlie  flooring  joists  of  the  uj)- 
per  stories. 
Fig.  45  rep- 


Fig.  45. 


Hollow  walls. 


Fig.  46. 


resents  this  apparatus  in 
position  for  laying  a  hoL 
low  concrete  wall,  not  intended  to  be  furred  on  the  inside. 
The  hollow  is  secured  by  means  of  a  movable  plank,  called  a 
core,  a  trifle  thinner  on  the  lower  than  on  the  upper  edge,  so 
that  it  can  be  moved  after  the  concrete  is  rammed  around  it. 
The  ties  between  the  inner  and  the  outer  walls  may  be  common 
bricks,  and  these  are  placed  under  the  core"  in  each  of  its 
positions,  as  the  building  progresses.  The  "  core"  is  notched 
on  the  lower  edge,  so  as  to  fit  down  upon  the  ties  flush  with 


232 


PRACTICAL  TREATISE  ON  LIMES, 


their  lower  beds.  Fig.  46  represents  a  side  view  of  the  core. 
The  width  of  the  hollow  should  be  from  two  to  three  inches,  the 
thickness  of  the  inner  wall  from  four  to  five  inches,  and  that  of 
the  outer  wall  ten  inches  and  upwards,  as  determined,  to  give  the 
requisite  strength.  The  hollow  is  sometimes  placed  in  the  centre 
of  the  wall,  a  practice  which  may  be  admissible  in  buildings 
not  intended  for  residences.  For  these  latter,  when  a  thickness 
of  five  inches  for  the  inner  wall  is  exceeded,  it  should  be  furred 
for  plastering,  to  prevent  the  condensation  of  moisture. 

460.  The  apparatus  in  common  use  on  the  continent  of 
Europe  and  in  some  portions  of  South  America,  in  constructing 
pise  work,  would  answer  in  forming  walls  of 
L^tS'work!"^  concrete,  and  would,  besides,  be  less  expen- 
sive, and  perhaps  more  easy  of  adjustment  and 
use  than  that  shown  in  Fig.  45.  It  consists  simply  of  a  box- 
ing of  planks,  kept  in  place  by  upright  posts  on  the  exterior, 
at  suitable  distances  apart,  say  four  or  five  feet.  The  lower 
ends  of  the  posts  are  mortised  and  keyed  into  horizontal  cross- 
pieces  called  futtocks,  which  reach  entirely  through  the  wall 
and  are  withdrawn,  and  the  holes  filled  up,  after  the  box  is 
filled  with  the  pise  or  concrete,  and  a  new  course  is  to  be  com- 
menced. The  upper  ends  of  the  posts  may  be  kept  in  position 
by  similar  cross-pieces,  but  the  more  common  practice  is  to 
confine  them  by  lashings  of  rope  or  cord,  tightened  or  loos- 
ened at  pleasure  by  a  stick  used  as  a  lever  for  twisting  up  the 
lashings.  The  wall  may  be  made  hollow  by  a  core  like  that 
shown  in  Fig.  45.* 

*  Pise  work  is  formed  of  clay  or  earth  rammed  in  layers.  The  best  material  is 
clay  which  contains  small  gravel,  and  is  of  such  consistency,  that  it  can  be  dug  with 
a  spade.  The  clay  must  first  be  thoroughly  beaten  up  and  passed  through  a  screen 
to  remove  stones  larger  than  a  hazel-nut,  and  then  moistened  to  a  uniform  consis- 
tency, so  that,  when  moulded  into  form  by  hand,  it  will  not  fall  to  pieces  under 
water.  In  forming  walls,  the  pise  is  rammed,  like  concrete,  in  layers  from  three 
to  four  inches  in  thickness,  care  being  taken  not  to  carry  up  the  walls  too  rapidly, 
lest  the  lower  portion  be  pressed  out  of  shape,  while  damp  and  plastic,  by  the  weight 
of  the  superincumbent  mass.  Except  in  very  dry  climates,  the  exterior  of  walls  in 
pise  should  be  protected,  by  a  coat  of  mortar,  from  the  action  of  rain.  The  walls 
should  be  thoroughly  dry,  before  being  plastered. 


.  HYDRAULIC  CEMEJNTS,  AND  MORTAES.  233 


461.  Within  the  last  ten  years,  the  practice  of  Hollow  concrete 
buildiiiff  concrete  houses  with  hollow  walls,  has    ^^'^^^^  becoming 

^-^  '  extensively  used. 

received  considerable  attention,  both  in  the 
United  States  and  in  Europe.    In  Sweden  and  Northern  Ger- 
many, it  is  quite  common.    The  facility  with 
which  the  fire,  smoke,  and  ventilating  flues  can  aSranteo-es! 
be  arranged  in  the  wall,  by  using  movable 
tubes  during  the  progress  of  construction,  the  partial  immunity 
from  risks  by  fire,  the  security  against  the  ravages  of  rats  and 
other  vermin,  and  the  equality  of  inside  temperature  through 
sudden  changes  of  weather,  secured  by  this  method  of  construc- 
tion, judiciously  followed,  specially  recommend  it  to  the  at- 
tention of  American  architects,  particularly  in  those  districts 
where  the  ingredients  of  concrete  are  plentiful  and  inexpen- 
sive, and  timber  or  good  building  stone  scarce.    There  are 
many  recent  examples  of  its  successful  application  among  us. 

462.  Fence  or  railing  posts,  of  the  minimum  size  consistent 
with  the  requisite  degree  of  strength,  may  be  firmly  set  and 
retained  permanently  in  their  upright  position  by  surrounding 
them  with  concrete,  or  rather,  by  inserting  them  in  a  concrete 
foundation.    The  mortar  for  this  purpose  need 

.  .  .         Post  foundations. 

not  be  very  rich  in  cement,  and  m  quantity, 
might  barely  exceed  the  volume  of  voids  in  the  coarse  mate- 
rials. One  foundation  properly  prepared  would  serve  for  an 
indefinite  period  of  time,  and  the  posts  could  be  renewed  as 
often  as  decay  rendered  it  necessary.  It  is  believed  that  by 
slightly  tapering  the  lower  end  of  the  posts  so  as  to  render 
their  removal  simple  and  easy,  and  by  lowering  the  entire 
foundation  so  as  to  place  its  upper  surface  below  the  reach  ot 
a  plough,  an  excellent  and  inexpensive  system  of  movable 
fences  for  farmers'  use  could  be  devised. 

463.  The  quick -setting  varieties  of  hydraulic  Use  of  cement  for 
cement  have  recently  been  quite  extensively  Mac^hf^ffor  mak- 
applied  to  drainage  and  sewerage  purposes,        the  pipes. 

in  a  mode  at  once  new  and  pecuHar.    The  mortar,  composed 


234 


PRACTICAL  TREATISE  ON  LIMES, 


FiR.  48. 


of  2  to  2^  measures  of  clean  coarse  sand  to  one  measure  of  the 
cement  powder,  mixed  with  a  small  quantity  of  water,  is  mould- 
ed into  pipe  in  sections  of  suitable  length,  say  about  three  feet, 
and  of  any  required  diameter  of  bore  up  to  3^  or  4  feet.  These 
sections,  on  being  joined  together  with  cement  mortar,  form  a 
continuous  water-tight  tube.  The  junction  may  be  secured  by 
means  of  the  ordinary  "  hub"  joint,  or  by  the  "  bevel"  joint 
referred  to  below. 

The  essential  parts  of  the  machine  for 
manufacturing  these  pipes  are  : 

First^  a  sheet-iron  cylindrical  "case"  in 
which  the  pipe  is  formed,  its  diameter  being 
of  course  the  same  as  the  exterior  diameter 
of  the  pipe.  This  cylinder  is  open  longitu- 
dinally on  one  side,  the  two  edges  along 
the  opening  being  turned  out  at  right  angles, 
thus  forming  flanges,  by  means  of  which 
the  case  can  be  firmly  held  together  with 
wooden  clamps. 

Second^  a  solid  cast-iron  cylindrical  "  core" 
equal  in  diameter  to  the  "  bore"  or  interior 
diameter  of  the  pipe.  When  this  "  core"  is 
placed  concentrically  in  the  case,  the  cylin- 
drical opening  between  the  two,  forms  the 
mould  for  the  pipe. 

Thirds  a  hollow  cylindrical  cast-iron  ram- 
mer or  "  plunger"  which  fits  over  the  core, 
so  as  to  pass  freely  between  the  "  core"  and 
the  "  case."  It  is  used  for  compressing  the 
mortar.  These  several  parts  are  represented 
separately  by  Figs.  48,  49,  and  50,  in  which 
a,  is  the  "  case"  clamped  together  at  ^,  i; 
h,  the  "  core,"  and  c,  the  "  plunger."  They 
are  combined  together  into  a  machine,  worked  by  hand,  which 
is  represented  by  Fig.  51,  in  which  A  is  the  outside  case  and 


Fig.  49. 


Fig.  50. 


HYDRAULIC  CEMENTS,  AND  MORTAES. 


235 


13,  the  "  core"  not  yet  in  position.    This  is  suspended  above 
the  case.    The  plunger  C  is  partially  seen  just  below  the 
hopper.      The  bottom  of 
the  mould  is  composed  of 
a  ring,  d,  d,  Fig.  49,  which 
gives  the  interior  of  one 
end  of  the  section  of  pipe 
the  bevel  form  of  joint.  A 
corresponding  exterior  bev- 
el on  the  other  end  of  the 
pipe  is  secured  by  making 
the  lower  end  of  the  plunger 
of  the  required  form  (see 
Fig.  48).    When  the  mould 
is  filled  the  core  is  forced 
down  into  a  pit  below  the 
machine,  leaving  the  mould- 
ed pipe  and  the  case  con- 
taining it  intact.    These  are 
then  set  on  one  side  until 
the  mortar  has  attained  such 
condition  of  hardness  that 
the  case  can  be  removed, 
which  is  easily  done  after 
the  clamps  are  taken  off. 

The  motion  of  the  plunger, 
(?,  the  pressure  on  the  mortar, 

and  the  removal  of  the  core,  2>,  are  all  regulated  by  suitable 
machinery  worked  by  hand,  which  need  not  be  explained. 
Different  sized  pipes  can  be  manufactured  with  the  same 
machine  by  changing  the  essential  parts,  that  is,  the  case,  core, 
and  plunger.  In  making  large  pipe,  the  plunger  is  dispensed 
with,  and  the  requisite  degree  of  density  conferred  by  constantly 
ramming  or  "  tamping"  with  crowbars.  The  bevel  on  the  upper 
end  is  then  formed  by  a  ring  (the  reverse  of  that  below)  forci- 


Fig.  51 


236 


PEACTICAL  TREATISE  OX  LIMES, 


bly  driven  on  when  the  case  is  full.  By  using  i  to  4J-  parts  of 
sand  to  one  of  cement,  the  pipe  becomes  porous  and  makes  a 
good  water  iilterer.* 

464.  In  laying  concrete  under  water,  an  essential  requisite 
Laying  concrete  ^^^^  should  not  fall  from  any  height,  but 
under  water.  be  deposited  in  the  allotted  place  in  compact 
masses,  otherwise  the  cement  would  be  washed  away  from 
the  other  ingredients,  thereby  seriously  affecting  the  strength 
of  the  work.  It  is  moreover  proper  that  the  concrete  should 
contain  a  larger  proportion  of  mortar,  and  that  this  latter 
should  be  rather  richer  in  cement  than  w^ould  111 
suffice  under  other  circumstances.  The  most 
common  method  of  depositing  concrete  is  by 
means  of  a  box  of  from  nine  to  twelve  cubic 
feet  capacity,  or  by  using  a  wooden  pipe  or 
conduit  with  its  lower  end  resting  on  the  posi- 
tion to  be  occupied  by  the  concrete.  A  modi- 
fication of  this  last  mentioned  de- 

Tremie  used  at  . 

Fort  Carroll,  Vice  was  used  in  laying  the  concrete 
Chesapeake  Bay.  fou^^jation  of  Fort  Carroll,  Chesa- 
peake Bay.  It  is  called  a  tremie  (Fig.  52),  is 
made  of  boiler  iron,  and  consists  essentially  of 
a  truncated  conical  base,  called  the  stock  or 
hopper,  and  a  vertical  shaft  in  five  sections. 
The  lower  section  is  permanently  attached  to  the 
base,  the  other  four  are  arranged  with  joints, 
and  can  be  readily  connected  together.  The 
tremie  is  suspended  on  a  wooden  frame  or  mov- 
able crane  having  four  cast-iron  wheels,  running  pig-,  52. 
on  a  railway,  by  means  of  which  the  whole  machine  is  moved 


*  Two  manufactories  of  this  pipe  are  in  operation  in  the  vicinity  of  New  York, 
viz. :  Pierce  &  Co.  Sixty-first  street,  near  Third  Avenue ;  and  Knight  &  Crawford, 
Jersey  City.  The  prices  of  some  of  the  principal  sizes  per  lineal  foot  are  as  fol- 
lows :  3  inch  bore,  8  cents  ;  6  inch  bore,  16  cents-  10  inch  bore,  30  cents ;  15  inch 
bore,  62  cents;  18  inch  bore,  85  cents. 


HYDEAULIC  CEMENTS,  AND  MORTARS.  237 


and  regulated,  as  the  work  progresses.  An  upward  and 
downward  motion  of  the  tremie,  by  which,  in  conjunction 
with  the  column  of  concrete  in  the  shaft,  the  materials  are  com- 
pressed as  they  issue  from  the  hopper,  is  secured  and  con- 
trolled by  a  powerful  screw  on  the  top  of  the  frame.  Thi8 
screw  is  worked  by  two  men. 

465.  The  sections  of  the  sea-wall  at  Fort  Carroll  filled  with 
concrete  by  the  tremie,  were,  in  the  clear,  8  feet  by  8  feet 
horizontal  section,  and  fourteen  feet  vertical  height,  equal  to 
896  cubic  feet  each.  The  time  occupied  in  filling  Q^j^ntity  of  work 
one  of  them  was  9  hours  51  minutes  (one  day), 

the  force  employed  consisting  of  29  men  including  the  over- 
seer. Of  this  time  2  hours  and  13  minutes  were  occupied  in 
filling  the  submerged  portion  of  the  tremie  stock,  at  the 
commencement  of  each  day's  operations.  This  was  done  by 
m-eans  of  a  cylindrical  tub  of  such  a  size  as  to  pass  freely  up 
and  down  within  the  tremie,  and  arranged  to  open  at  the  bot- 
tom, like  the  concrete  box  described  in  paragraph  466,  Fig. 
53.  The  tremie  stock  was  filled  in  this  manner,  until  the  con- 
crete rose  above  the  level  of  the  water. 
After  this,  the  concrete  was  thrown  into 
the  tremie  with  hods.  In  deep  water, 
it  is  sometimes  necessary  to  load  the 
tremie.  It  is  important  that  the  upper 
surface  of  the  column  of  concrete  should 
be  kept  above  the  surface  of  the  water. 
When,  in  the  progress  of  the  work,  the 
base  of  the  hopper  reaches  the  w^ater 
level,  the  tremie  is  dispensed  with,  and 
the  concrete  is  rammed  in  the  usual  way. 

466.  Fig.  53  represents  an  end  view 
of  the  semi-cylindrical  box  for  lowering 
concrete.    It  is  in  two  parts,  which  join 
along  the  line  o\  a,  and  open  around  the  Fig.  53. 
hinge,  o\  so  as  to  let  the  concrete  through  the  bottom.  A 


238 


PRACTICAL  TREATISE  O'N  LIMES, 


pin  at  a  keeps  the  two  parts  together  until  the  box  reaches 
the  desired  position,  when  it  is  withdrawn  by 

Box  for  lowerino'  r>  ,  i  -, 

concrete  in  water.     ^^^^^ns  of  the  COrd,  C. 

It  opens  at  the         After  the  concrete  is  placed  in  the  box,  the 

bottom. 

top  should  be  closed  by  sheet-iron  covers,  s,  s, 
to  prevent  a  rush  of  water  over  the  mixture. 

467.  An  improvement  in  the  device  for  fastening  the  two 
parts  of  the  box  together,  and  one  which,  while  it  would 
render  it  impossible  for  careless  or  unfaithful  workmen  to  open 

the  box  prematurely,  and  allow  the  cement  to 

An  improved  fast-        „  , 

ening,  which  be-  lall  through  the  water,  would  also  secure  a  con- 
wiK^r  th^*^ box  ^'  siderable  saving  of  labor,  has  been  recently  in- 
tom^^^     ^^**      ti'^^cluced  by  M.  Sesquieres,  Superintendent  of 

Roads  and  Bridges  in  France.  The  box  is  of  a 
prismatic  form,  of  -pj/V  cubic  yards  capacity,  and  the  bottom  of 
it  opens  of  its  own  accord,  when  it  reaches  and  rests  upon  the 
soil  or  the  concrete  previously  laid,  and  not  before.  This  re- 
sult is  secured  by  a  bar,  attached  longitudinally  to  the  lower  part 
of  the  box,  and  carrying  a  latch  on  each  extremity,  working 
into  corresponding  catches  in  such  a  way  that  an  upward  pres- 
sure on  the  bar,  obtained  in  eifect  when  the  loaded  box  is  low- 
ered to  its  position,  unfastens  the  bottom,  allowing  the  mass  of 
concrete  to  fall  out  when  the  box  is  raised  again.  M.  Ses- 
quieres prefaces  his  description  of  this  box,  in  the  Annales  des 

Fonts  et  Chaussees,  for  1854,  by  the  following 
Se^squie^res^^  ^'      I'emarks  :  "  Frior  to  the  year  1841,  '  beton'  was 

laid  under  water  in  the  hydraulic  works  exe- 
cuted in  the  Department  of  Tarn  and  Garoune  by  means  of  a 

box,  of  the  form  of  a  truncated  pyramid,  suspend- 

Depositmg  con-  '   ^  ^  .  . 

Crete  by  inverting  ed  at  its  extremity  by  a  rope,  winding  around  an 
axle  worked  with  heaving  bars  ;  a  rope  is  also  at- 
tached to  the  middle  of  the  bottom  of  the  box,  by  means  of  which 
it  can  be  inverted  in  order  to  empty  it.  This  method  is  defec- 
tive, as  the  box  must  be  turned  upside  down  to  be  emptied,  which 
operation  cannot  be  performed,  unless  the  box  is  suspended  at  a 


HYDRAULIC  CEMENTS,  AISTD  MOETARS. 


239 


certain  height  above  the  bottom  of  the  water  ;  the  consequence 
is  that  the  beton  becomes  divided  and  washed  off,  so  that, 
when  it  reaches  the  bottom,  nothing  is  left  of  it  but  sand  and 
pebbles.  An  unscrupulous  contractor  could  even  empty  the 
box  as  soon  as  it  had  disappeared  under  the  water,"  &c. 

468.  It  may  be  remarked,  however,  that  among  French  en- 
gineers, the  relative  advantages  of  the  two 

r>        T       /  Relative  advan- 

methods  oi  depositing  con(;rete  reierred  to  (one    tages  of  the  two 

by  inverting  the  box,  and  the  other  by  opening    methods  of  depos- 

'J  in  5  .7     r  iting  concrete  not 

it  at  the  bottom),  have  not  yet  been  definitely    settled  by  French 
settled,  some  preferring  and  practising  one,  and 
some  the  other.    The  size  of  these  caisses  a  immersion  is  also 
a  question  still  in  controversy.    M.  Baudenioulin  recommends 
the  capacity  of  y',^  cubic  metre.    Experience  seems  to  show 

that  larsfer  ones  are  better,  as  not  favorino^  the 

^  .  The  size  of  boxes 

formation  of  large  quantities  of  laitancef^  At  also  a  question  of 
Calais,  boxes  of  yV  cubic  metre  (3J  cubic  feet)  ^^^^^^'^'^^sy. 
capacity  were  first  used  by  M.  Nehon ;  these  were  subsequent- 
ly replaced  by  those  of  \  cubic  metre  (1 1\  cubic  feet)  capacity, 
which  in  their  turn  gave  way  to  others,  tirst  of  1  and  then  of  2 
cubic  metres  capacity,  the  constant  aim  being  to  lessen  the 
volume  of  laitance  formed.  Preference  was  given  to  large 
sizes. 

469.  It  is  considered  injurious  to  ram  concrete  deposited 
under  water.    To  obtain  the  necessary  density,    concrete  not  to 
we  must  depend  on  the  rake  or  some  similar    be  rammed  under 

1  11  11  water. 

instrument  gently  used,  to  keep  the  layers  ap- 
proximately level,  and  on  the  weight  of  the  superincumbent 
mass.    Some  eminent  French  engineers  recommend  the  forma- 
tion in  a  single  mass  or  layer  of  concrete  work 

,  ,  ,    ^,        J?  *£.       J  1  .      Formation  of  sub- 

under  water,  wli ether  tor  toundations,  plat-    merged  masses  of 

forms,  or  areas.    The  only  advantage  to  be  de-    ^^^^''^^^^  ^^^^^^ 

'  .  mass. 

rived  from  this  method,  over  the  one  of  thin, 

continuous  layers  formed  successively  over  extensive  areas,  ap- 

*  See  paragraph  474  on  the  subject  of  laitaryie 


240 


PEACTICAL  TREATISE  ON  LIMES, 


pears  to  be  the  increased  density  of  the  portion  first  laid. 
This,  before  it  begins  to  set,  becomes  well  compressed  by  the 
weight  subsequently  added. 

470.  In  founding  with  concrete,  it  is  usual 
pHes.^  ^     '  surround  the  place  to  be  occupied  by  the 

work  with  sheet-piles,  driven  somewhat  below 
the  level  of  the  base  of  the  structure,  and  then  to  remove  the 
When  sheet-piles    ^^^^  requisite  depth.    In  certain  cases, 

can  be  dispensed  when  the  soil  is  very  firm,  and  the  foundation 
with.  ' 

has  to  reach  to  a  small  depth  only,  the  piling 

need  not  be  used  ;  in  others  where  these  conditions  do  not  ob- 
tain, it  may  be  necessary  to  use  piles  of  extra  strength  and 
length,  and  to  support  them  against  the  pressure  of  the  earth 
To  prevent  cur-  by  braces  at  top.  In  order  to  prevent  currents 
wash  the^on?^^     that  might  wash  the  concrete,  holes  should  be 

left  in  the  piling  near  the  top,  so  that  the  water 
will  remain  at  the  same  level  within  and  without.   In  founding 

over  springs,  the  action  of  which  might  drench 
Precautions  when    the  concrete,  and  wash  out  the  cement,  they 

founding  over  •  i    i  i        i  i 

springs.  might  be  stopped  oii  by  tarred  canvas  stretched 

over  the  area.. 

471.  Concrete  walls  are  frequently  revetted  or  faced  with 
stone.    In  fact,  this  is  a  common  method  at  the  present  day  of 

constructing  sea-walls,  and  sustaining  walls, 
oftonrte  walls.    The  stone  facing  is  generally  in  courses,  com- 

posed  of  headers  and  stretchers  alternately. 
The  stretchers  are  so  jointed  on  the  end  as  to  be  a  few  inches 
longer  on  the  back  than  on  the  front.  The  vertical  joints  on 
the  headers,  being  formed  at  a  corresponding  angle  with  the 
face,  while  the  tails  of  the  headers,  reaching  entirely  through 
the  concrete  backing,  are  left  undressed,  the  wall  becomes  a 
firm  and  connected  system  of  dovetailing.    In  constructing  a 

wall  of  this  kind,  as  soon  as  a  course  of  facing 

Manner  of  eon-  ^       ^  ...  . 

Btructing  such  a     stone  is  laid,  the  back  to  its  entire  thickness  is 
levelled  up  with  concrete,  rammed  in  compact 


HYDEAIJLIC  CEMENTS,  AND  MOETAES.  241 


layers  not  exceeding  one  foot  in  depth,  the  surfaces  of  the  stone 
having  previously  been  freed  from  dust,  moistened  with  water, 
atffl  coated  over  with  mortar,  in  order  to  insure  the  adhesion 
of  the  concrete. 

472.  Submarine  walls  of  this  description  cannot  be  laid 
without  exhausting  the  water  within  the  area  to  be  built  upon, 
or  using  the  diving-bell,  or  some  other  method  of  subaqueous 
construction. 

473.  For  laying  the  sea-wall  for  the  cover-face  of  Fort  Tay 
lor,  located  in  7  ft.  of  water,  at  mean  low  tide,  Major  Hunt, 
of  the  Corps  of  Engineers,  devised  a  coffer-    Description  of 
dam  surrounded  with  a  canvas  case.     This    devised^b^  M^j 
case  consists  of  two  parts  firmly  sewed  together,  Hunt. 

viz. :  the  upright  part,  or  case  proper,  and  the  fl.ap.  The  case, 
when  in  use,  stands  vertically  against  the  sheathing  of  the 
dam  on  the  exterior,  and  its  height  should  exceed  somewhat 
the  depth  of  the  water  where  it  rests.  The  flap  lies  out  on  the 
bottom,  and  has  a  width  of  20  ft.  all  around  the  case,  its  object 
being  to  cut  off  infiltration  through  porous  soils,  when  the 
coffer-dam  is  exhausted  of  water.  The  size  of  case  at  Fort 
Taylor  is  adapted  to  laying  nearly  50  running  feet  of  wall. 
In  order  to  connect  the  section  under  construction  with  the 
part  previously  laid,  a  slit  is  left  in  the  case,  at  one  end. 

.474  When  concrete  is  deposited  in  water,  a  pulpy,  gelatin- 
ous fluid  is  washed  from  the  cement,  and  rises  to  the  surface. 
This  causes  the  water  to  assume  a  milky  hue,  hence  the  term 

laitance.  which  French  ensiineers  apply  to  this 

,     .  .         /  1  -,  Laitance. 

substance.    As  it  sets  very  imperiectly,  and, 

with  some  varieties  of  cement,  scarcely  at  all,  its  interposition 
between  the  layers  of  concrete,  even  in  moderate  quantities, 
will  have  a  tendency  to  lessen,  more  or  less  sen- 
sibly, the  continuity  and  strength  of  the  mass,  effelti!*"'^''* 
This  pulp  is  produced  more  abundantly  in  sea- 
water  than  in  fresh  water.    Its  composition,  as  determined  at 
the  "  Ecole  des  Ponts  et  Chaussees"  in  1856,  is  given  below. 
16 


242 


PRACTICAL  TEEATISE  ON  LIMES, 


The  sample  was  a  thick  jelly,  of  a  dirty  white  color,  possessing 
d,n  alkaline  reaction,  and  was  produced  in  laying  concrete  in 
the  Mediterranean  Sea. 

The  analysis  gave  the  following  results : 


Analysis  of 
laitance  from 
the  Mediterra- 
nean Sea. 


Insoluble  in  water 


Silicious  sand   2.888 

Silica  2.692 

Carbonic  acid   2. 5^0 

Alumina  and  traces  of  iron  34t 

Free  caustic  lime  345 

Combined  lime  3.998 

L  Magnesia   2.027 


Total  insoluble  in  water  14.867 

Soluble  in  water   3.462 

Water  and  loss  81.671 


100.000 


475.  The  water  of  the  Mediterranean  contains  nearly  three 
pounds  of  magnesia  per  cubic  yard,  and  the  theory  of  this  pulpy 
Theory  of  the  formation  is  that  the  immersed  concrete  gives 
formation  of         up  to  the  Water  free  caustic  lime  in  a  finely  di- 

laitance.  •  i    i  ^  •  ■,  .   .  .  . 

vided  state,  which  precipitates  magnesia  m  a 
light  and  spongy  form.  This  precipitate,  interposing  itself 
among  particles  of  the  mortar  thrown  into  suspension  by  the 
motion  of  the  liquids,  produces  the  laitance  so  much  com- 
How  the  evil  plained  of.  The  evil  might  be  lessened  by 
might  be  operating  in  a  limited  space  where  the  sea- water 

could  not  be  constantly  renewed,  or  by  using 
mortars  possessing  sufficient  hydraulic  activity  to  retain  all 
The  laitance  is  t^ieir  free  caustic  lime  ;  but  the  usual  means  is 
usually  removed  to  use  several  pumps  for  its  removal.  These 
by  pumps.  should  not  be  too  large  and  powerful,  on  account 

of  the  injurious  effects,  on  the  mortar,  of  strong  currents;  even 
small  ones  should  be  operated  with  care.  The  proportion  of 
the  laitance  is  greatly  diminished  by  using  large  immersing 
boxes,  say  of  one  to  one  and  a  half  yards'  capacity. 

4:76.    The  nature  and  size  of  the  coarse  ingredients  of  con 


HYDEAULIC  CEMENTS,  AND  MORTAKS. 


243 


Crete  will  depend,  of  course,  upon  local  circuin- 

,  -iTT-r,  .    ,  p  1        J       1,      Nature  and  size 

stances.    W  hen  a  mixture  oi  gravel  and  peb-    of  the  coarse 
bles  can  be  had,  at  a  slidit  advance  on  the  cost    ingredients  of 

'  Y  concrete. 

of  collecting  the  same,  it  is  generally  used,  on 
the  score  of  economy,  in  preference  to  fragments  of  brick 
or  stone.    For  a  similar  reason,  oyster-shells  are  sometimes 
used,  almost  exclusively. 

477.  When  concreting  is  carried  on  in  connection  with  stone- 
cutting,  and  stone-masonry  operations  in  gen- 
eral, the  spalls,  chips,  and  irregular  fragments  chips. 
made  by  the  cutters,  can  be  converted  into  ex- 
cellent concrete  material  at.  a  moderate  cost.    This  cost  will,  of 
course,  vary  somewhat  with  the  kind  of  masonry  and  the 
quality  of  cutting,  generally  ranging,  however,  between  fifty- 
five  and  seventy  cents  per  cubic  yard  for  labor  only,  allowing 
nothing  for  the  refuse  stock  used. 


Fisr.  54. 


478.  The  preparation  of  concrete  material  by    Breaking  con- 

^     ^  ••111       Crete  by  hand  an 

hand,  from  large  masses  of  stone  is  considerably    expensive  opera- 
tion. 

more  expensive. 

479.  Figure  54  shows  a  longitudinal  section  of  the  essential 


244 


PEACTICAL  TREATISE  ON  LIMES, 


parts  of  a  stone-breaking  machine  in  use  on  the  New  York 
Central  Park.    A,  A',  A",  A'"  is  the  frame  of 

Stone-breaking  ,  .         •         .     ,       .  ,  .  ,  .  , 

machine  used  in  cast-iron  m  a  smgle  piece,  which  receives  and 
New  York  and      supports  the  Other  parts.    This  frame  consists  of 

elsewhere.  ^  ^  ^ 

two  parallel  cheeks  A  connected  together  by 
the  parts  A',  A,  "A'''  (shaded  with  diagonal  lines).  The  arc,  B, 
represents  a  fly-wheel,  of  which  there  are  two,  one  on  each  side 

of  the  frame,  working  on  a  shaft  having  its 
^Zt^^^""  bearing  on  the  frame.    This  shaft  is  formed 

into  a  crank  E  between  the  bearings,  and  car- 
ries a  pulley  C  to  receive  a  belt  from  a  steam-engine  or  other 
driver.  The  fly-wheel,  the  section  of  fly-wheel  shaft,  the  pul- 
ley, and  the  arc  described  by  the  centre  of  the  crank  in  its  revo- 
lution, are  indicated  by  dotted  circles.  F  is  a  pitman  or  rod 
which  connects  the  crank  with  the  lever^  G.  This  lever  has  its 
fulcrum  on  the  frame  at  H.  A  vertical  piece  I  stands  upon 
the  lever  against  the  top  of  which  piece  the  toggles  J  J  have 
their  bearings,  forming  an  elbow  or  toggle-joint.  K  is  fixed 
jaw^  against  which  the  stones  are  crushed.  This  is  bedded  in 
zinc  against  the  end  of  the  frame,  and  held  back  to  its  place  by 
cheeks  L  that  fit  in  recesses  in  the  interior  of  the  frame  on  each 
side.  M  is  the  movable  jaw.  This  is  supported  by  the  round 
bar  of  iron  K  which  passes  freely  through  it,  and  forms  the 
pivot  upon  which  it  vibrates.  O  is  a  spring  of  India  rubber, 
which  is  compressed  by  the  forward  movement  of  the  jaw,  and 
aids  its  return. 

Every  revolution  of  the  crank  causes  the  lower  end  of  the 
movable  jaw  to  advance  towards  the  fixed  jaw  about  \  of  an 
inch  and  return.  Hence,  if  a  stone  be  dropped  in  between  the 
convergent  faces  of  the  jaws,  it  will  be  broken  by  the  next  suc- 
ceeding bite ;  the  resulting  fragments  will  then  fall  lower  down 
and  be  broken  again,  and  so  on,  until  they  are  made  small 
enough  to  pass  out  at  the  bottom.  The  distance  between  the  jaws 
at  the  bottom  limits  the  size  of  the  fragments,  and  may  be  regu- 
lated at  pleasure.    A  variation  to  the  extent  of  f  of  an  inch 


HYDEAULIC  CEMENTS,  AND  MOETARS. 


245 


may  be  made  by  turning  the  screw-nut,  P,  which  raises  or  lowers 
the  wedge^  Q,  and  moves  the  toggle-hloch^  R,  forward  or  back. 
Further  variations  may  be  made  by  substituting  for  the  toggles, 
J  J,  or  either  of  them,  others  that  are  longer  or  shorter ;  ex- 
tra toggles  of  different  lengths  being  furnished  for  this  pur- 
pose. 

The  broken  stone  passes  from  the  machine 

Screening  of  the 

mto  a  revolving  cylindrical  screen  standmg  at  broken  stone, 
an  inclination  to  the  horizon,  by  means  of  which 
the  material  is  separated  in  fine,  medium  size,  and  coarse  stone. 
The  meshes  of  this  screen  are  small  at  the  upper  end,  medium 
size  at  the  middle,  and  large  at  the  lower  end.  Fragments 
which  pass  entirely  through  the  cylinder  are  returned  to  the 
machine  and  broken  again. 

480.  The  product  of  these  machines  per  hour,  in  cubic 
yards  of  fragments,  will  vary  considerably  with  the  character 
of  the  stone  broken.  The  proper  speed  is  about  200  revolutions 
per  minute. 

481.  The  following  table  will  give  an  idea  of  the  capacity  of 
these  stone-breakers : 


TABLE  XYII. 


Sizo  of  chamber  at  top. 

Product  per  hour. 

Power  required. 

10"  X  5" 
15" X  5" 
20"  X  1" 

3  cubic  yards. 
6  " 

6  horses. 
9  " 
12  " 

Capacity  of  the 
machine. 


482.  Another  excellence  of  the  machine  is  the  superior  quali- 
ty of  its  work.  For  concrete,  a  cubic  yard  of  stone  requires 
about  25  per  cent,  less  of  cement  than  stone  broken  by  the 
hammer,  for  the  reason  that  the  former  packs  closer.  The 
harder  the  stone,  within  certain  limits,  the  greater  the  quantity 
the  machine  w^ill  break,  as  the  product  runs  off  more  freely. 
Tlie  15-inch  machine  weighs  about  8,100  lbs  ;  the  10-inch,  5,800. 


246 


PRACTICAL  TEEATISE  ON  LIMES, 


483.  Concrete  foundations  of  Forts  Richmond 
crX  of  F^ortT"  ^'^^  Tom:pkins,—T\ie  concrete  for  the  founda- 
Richmond  and       tions  of  Forts  Eichmond  and  Tompkins,  New 

Tompkins. 

York  harbor,  was  composed  of  hydraulic  cement, 
sand,  and  granite  fragments  in  the  following  proportions, 
viz : — 

1  cask  (308  lbs.  net)  of  hydraulic  cement  which  produced  3.65  to  3.70  cubic 
feet  of  stiff  paste. 

3  casks  or  12  cubic  feet  of  loose  sand,  equal  to  9.15  cubic  feet  well  compacted, 

The  sand  and  cement  being  well  incorporated,  yielded  11.75 
cubic  feet  of  rather  thin  mortar,  to  which  were  added  5  casks 
(20  cubic  feet)  of  granite  fragments,  producing  a  batch  of 
concrete  measuring  21.75  cubic  feet  when  rammed  in  the 
foundation. 

Concrete  for  su-  484.  Concrete  for  swperstructures  at  Forts 
FortrRt'hmond  ^iGhmond  and  Tomjpkins.—Fov  superstruc- 
and  Tompkins.  tures,  the  concrete  contained  11.75  cubic  feet  of 
mortar  as  above,  and  16  cubic  feet  of  broken  stone  fragments. 

485.  The  concrete  foundation  of  Fort  Tompkins  contained 
about  one-twelfth  of  its  bulk  of  stone  masses  of  various  dimen- 
sions, measuring  from  J  to  f  of  a  cubic  foot,  each  rammed  into 
the  heart  of  the  wall  as  the  concrete  was  laid. 

486.  Cost  of  concrete  foundation  of  Fort  Tomjpkins. — Esti- 
mating the  cement  at  85  cents  per  barrel,  (which  was  the  average 
Cost  of  concrete  of  pi"ice  during  the  summer  of  1859,  when  that 
Fort  Tompkms.  portion  of  the  work  supplying  these  data  was 
laid),  the  broken  stone  at  eight  cents  per  barrel,  which  is  merely 
the  cost  of  the  labor  expended  in  reducing  the  chippings  of  the 
stone-cutters  to  the  proper  size  for  concrete,  and  allowing  six 
cents  per  barrel  for  excavating  and  screening  the  sand,  which 
was  procured  from  a  deposit  close  at  hand  on  the  premises,  and 
nothing  for  water,  the  cost  of  the  concrete  was  $2.46  per  cubic 
yard,  rammed.  This  was  reduced  to  $2.26  per  cubic  yard,  by 
the  introduction  of  the  unbroken  masses  of  irregular  size, 
allowing  nothing  for  the  granite  stock  thus  consumed.  These 


HYDRAULIC  CEMENTS,  AND  MORTAES.  247 


results  are  the  averages  of  an  entire  season's  operations,  as 
exhibited  in  the  following  table  : 

48T.     TOTAL  COST   OF  LABOR   AND  MATERIAL  EXPENDED  IN  LAYING  CONORHTB 


FOUNDATION  AT  FORT  TOMPKINS,  DURING  THE  YEAR  1849. 

Labor. 

Wages  of  sub-overseer  42.2  days  at  $2  per  day   $84  40 

"       mason  setting  plank  82.8  days  at  $2  per  day   165  60 

"       laborers  assisting)  153.6  days  at  $1  per  day   153  60 

**      laborers  transporting  and  ramming  concrete  2,911.8  days  at 

$1  per  day   2,971  80 


Total  cost  of  labor  $3,3t5  46 


Materials. 

4,096  casks  cement  at  85  cents  $3,481  60 

12,288    "     sand  at  3  cents   368  64 

20,480    "     broken  stone  at  8  cents   1,638  40    5,488  64 

Total  cost  of  labor  and  materials  $8,864  04 

Total  number  of  cubic  yards  of  concrete  laid,  excluding  the  stone 

masses  rammed  in  3,60637 

Cost  per  cubic  yard  of  pure  concrete   $2  46 

Deduct  for  stone  masses  rammed  in   20 

Cost  per  cubic  yard  as  laid   2  26 

If  the  price  of  the  cement  had  been  the  same  as  at  Fort  "Warren,  viz. ;  ^ 
cent  per  lb.,  the  cost  of  one  cubic  yard  of  pure  concrete  would  have 
been   3.52 

488.  The  following  is  an  analysis  of  the  composition  and  cost 
of  the  concrete  employed  for  laying  the  foundations  of  the 
sea-wall  at  Lovell's  Island,  Boston  harbor : 

1  barrel  of  cement,  308  lbs.  net ... .  > 

3.70  cubic  feet  of  paste.'  J   ^^'^^ 

8  cubic  feet  sand  at  51  cents  per  ton   .20 

Labor   .09 

Cost  of  10  cubic  feet  mortar   $1.83 

Gravel,  30  cubic  feet   .28 J 

Making  concrete,  .130  day  ^ 

Transporting  do.,  .065    "  V  ,   =.28 

Packing        do.,  .037  "   ) 

Tools,  implements,  &c   .13 


Cost  of  32.30  cubic  feet  of  concrete, 
Cost  of  1  cubic  yard  laid  


2.52i 
$2.11 


248  PEACTICAL  TREATISE  ON  LIMES, 

489.  For  the  concrete  backing  of  the  sea-wall  at  Lo veil's 
Island,  the  proportions  exhibited  in  the  following  analysis  were 
adopted : 

Cement,  1  cask  =  308  lbs.  =  3.70  cubic  feet  paste  $1.54 

Sand,  812  lbs.  =:7.89  cubic  feet  dense,  producing  9.8  cubic 

feet  mortar  21 

Gravel,  26.4  cubic  feet  25 

Making  mortar  065 

Making-  concrete  02 

Transporting  do  065 

Packing        do  09 

Tools,  implements,  &c  12 


.24  day. .  .40 


Cost  of  1.09  cubic  yard  «=»  2.52 
Cost  of  1  cubic  yard  laid  =  2.31 

Concrete  may  490.  Concrete  containing  common  lime. — Ex- 
contain  a  large  . 

proportion  of  ccpt  iinder  circumstances  of  rare  occurrence, 
common  lime,  concrete  may  receive  a  large  proportion  of  the 
paste  of  fat  lime  without  serious  prejudice  to  its  hydraulic  en- 
ergy and  strength,  and  with  great  advantage  on  the  score  of 
economy. 

491.  For  founding  above  water  level,  the  following  propor- 
tions have  been  employed  in  Boston  harbor,  and  elsewhere : 

Cost  of  con-      Cement,  1  barrel  =  308  lbs.  =3.70  cub.  ft.  paste.  .,.$1.54 

Crete  contain-       Lime,  \  cask,  =  2.50  cub.  ft  paste  22 

ing  lime.  Sand,  .67  ton  =14.6  cub.  ft.  dense  33 

Producing  .475  cub.  yds.  mortar  =  12.825  cub.  ft. 

Making  mortar  in  mills,  .475  yds.,  at  39  c  18^ 


Cost  of  .475  yds.  =  12,825  cubic  feet  of  mortar   $2.27^ 

Granite,  21.249  cubic  feet,  at  70  c.  per  yd  55| 

Gravel,  .61  ton,  at  50c  per  ton  30|^ 

Making,  carrying,  and  packing  concrete  42 — 1,28 


Cost  of  1.355  cub.  yd.  concrete   $3.55^ 

Cost  of  1  cub.  yd.  concrete,  laid   $2.62^ 

492.  If  we  increase  the  volume  of  lime  paste,  in  the  concrete 
last  mentioned,  to  four  times  that  of  the  ce- 
JS^a^tat^of  toe.     «ient  paste,  thereby  giving  to  the  mortar  the 
following  composition,  viz. : 


HYDEAULIC  CEMENTS,  AND  MOKTARS. 


249 


Cement  paste  1.24  cubic  feet. 

Lime  paste  4.96    "  " 

Sand  16.6     "  " 

The  corresponding  cost  per  cubic  yard  of  concrete  will  be   $2.03 

493.  It  is  customary  to  cover  the  upper  tier  of  arches  in 
casemated  fortifications  with  concrete,  formed,  for  carrying  off 
the  water,  into  ridges  and  valleys,  by  a  series  of  inclined  plane 
surfaces,  which,  after  receiving  a  coating  of  lime  mortar,  are 
covered  with  bituminous  mastic.    This  mastic  adheres  but  in- 
differently to  cement  mortar,  which,  on  account    Bituminous  mas- 
of  its  comparative  impermeability  to  air  and    here^weii  to  con- 
moisture,  does  not  absorb  the  steam  and  rari-  crete. 
fied  air  produced  when  the  hot  mastic  is  applied.    The  sepa- 
rating medium,  thus  interposed  between  the  mortar  and  the 
mastic,  produces  air  bubbles  in  the  latter  while  hot,  thereby 
seriou-sly  impairing  its  quality  as  a  covering ;  objections  which 
do  not  obtain  when  lime  mortar  is  used.  In 
cases  where  the  concrete  covering  is  not  relied  Remedy, 
upon  in  part  to  render  the  casemates  bomb 
proof,  the  principal  portion  of  the  roofing,  being  intended  sim- 
ply to  give  the  required  form  to  the  roof  surfaces,  may  be  of  a 
cheap  quality  of  concrete,  enough  cement  being  used,  however, 
to  insure  its  setting  sufficiently  quick  to  prevent  interruption 
to  the  progress  of  the  work.    The  composition  given  above, 
estimated  to  cost  $2.03  per  cubic  yard,  would  perhaps  be  good 
enough  for  this  purpose.    The  upper,  or  exterior  portion,  to 
the  depth  of  five  or  six  inches  should  be  rich  and  contain  no 
lime.    The  following  is  the  analysis  of  that  used  at  Fort 
Warren  for  this  outer  coat : 

Cement  308  lbs.  =  3.70  cub.  ft.  of  paste  1.54 

Sand  (including  waste)  7.4  cub.  ft.  =  .372  ton,  at  50  c  18^ 

Broken  bricks,  15.4  cub.  ft.  =  .57  cub.  yds.  at  35  c.  per  yd.  .20  °f  ^^f^^?* 

xx  ^•          4.     ^,  n     uiv^on  T,     concrete  at  Fort 

Makmg  mortar,  7.7  cub.  ft.  at  39  c.  per  cub.  yd  11  barren. 

Making,  transporting,  and  packing  concrete,  &c  40^ 

Cost  of  18.5  cub.  ft.  of  concrete  $2  44 

Cost  per  cubic  yard,  laid  ,  3.56 


250 


PEACTICAL  TEEATISE  OlS^  LIMES, 


494.  Some  blocks  of  concrete  were  made  in  the  harbor  of 
New  York,  in  1860,  in  the  course  of  these  experiments,  by  in- 
jecting a  thin  paste  of  light  colored  Rosendale  cement  without 
sand,  into  boxes  filled  with  coarse  gravel  and 
bj^a^pastfo™^^  pebbles,  and  submerged  in  sea-water.  The 
cement  injected      cement  was  mixed,  in  some  cases  with  fresh,  in 

under  water.  ^  ' 

others  with  sea  water,  in  the  proportion  by 
volume  of  48  of  water  to  100  of  cement  powder.  It  was 
poured  through  a  tin  pipe  1^  inches  in  diameter  and  18  feet 
in  vertical  height.  The  boxes  were  5yVx5y»o-"x36"  clear 
dimensions,  and  were  perforated  with  small  holes,  to  facilitate 
the  ejection  of  the  water.  At  the  expiration  of  some  weeks, 
the  boxes  were  taken  from  the  water,  and  the  blocks  removed. 
The  cement  was  found  to  have  penetrated  to  the  remotest 
corners  of  the  boxes,  and  to  have  filled  perfectly  the  interstices 
in  the  gravel  and  pebbles. 

^    .    -,      495.  The  cement  mixed  with  sea-water  fur- 

The  paste  mixed 

with  sea-water  nished  by  no  means  a  stable  concrete.  A  few 
not  good.  dsLjs,  after  exposure  to  the  air,  it  began  to  crack 

all  over  the  surface,  and  was  very  deficient  in  cohesive 
strength  and  solidity. 

That  mixed  with  fresh  w^ater  retained  its  sharp  corners  and 
angles  perfectly ;  no  cracks  or  other  evidences  of  decomposition 
appeared.  The  blocks  remained  solid  and  compact  and  when 
broken  for  examination  it  appeared  that  the  adhesion  to  the 
pebbles  was  very  good,  and  that  every  void  was  perfectly 
filled. 

496.  There  is  reason  to  believe  that  the  cream  of  cement 
would  be  improved  by  the  addition  of  8  to  10  per  cent,  of  fat 
lime  paste,  and  that  the  long  pipe  can  be  advantageously  re- 
placed by  a  syringe  or  force  pump  of  suitable 
The  cement  paste     n  n         '        •  i     .  2.^    j.  j.i  i  ^ 

would  be  im-         torm  ;  tor  it  IS  evident  that  the  pressure  due  to 

proved  by  a  little    the  vertical  height  of  the  pipe,  supposing  a 
perfect  fluid  to  be  used,  is  only  partially  se- 
cured by  the  semi-fluid  cement,  and  can  only  be  augmented  by 


HYDEAULIC  CEMENTS,  AND  MORTARS. 


251 


thinning  the  paste,  or  by  lengthening  the  pipe.  Any  arrange- 
ment,  by  means  of  which  a  stiffer  paste  can  be  injected,  would 
be  an  improvement. 

497.  We  infer  from  the  foregoing  results  that  a  thin  paste 
of  Eosendale  cement  is  worthless  for  concrete,  if  mixed  up 
with  sea-water,  while  with  fresh  water,  it  will  harden  when 
injected  nnder  water,  either  fresh  or  salt,  and  affords  the 
means  of  submarine  construction,  that  may  be  of  great  value 
under  certain  circumstances.  ' 

498.  TABLE  XYin  * 


Mortars. 


Composition 
in  volumes. 


.62 


.43 


.38 


.35 


.34 


32 


1.69 


1.24 


1.12 


1.05 


.96 


Concretes. 


Compo- 
sition in 
volumes 


1.56 
1.03 
1.— 
1.— 


1.45 
1.11 
1.00 

1.40 
1.11 
1.03 

1.40 
1.14 
1.01 

1.45 
1.13 
1.03 

1.45 
1.13 
1.03 


Resistance  of  the  concrete  to  rupture. 


W,  or  breaking  vpeight  in 
lbs.  found  by  experi- 
ments. 


10  days, 


1,087 
800 
856 
492 


20  days, 
lbs, 


1,093 
1,322 
1,065 
646 


778  889 
778  954 
492  668 


404 
315 
271 

227 
149 
163 

141 
114 
114 

191 
136 
176 


448 
463 
359 

346 
289 
240 

304 
218 
202 

192 
196 
181 


a 

«j  ? 


Calculated  value  of  72,  or 
resistance  per  square 
inch  to  a  force  of  exten- 
sion. 


60  days,  o  'C  : 
lbs.  ^1=^'^ 


1,376 
1,504 
1,480 
481 


1294 
1016 
906 

430 
633 
600 

542 
437 
404 

392 
326 
306 

381 
337 
370 


92 
99 
95 
92 


10  days.  20  day.s.  60  days, 
lbs.        lbs.  lbs. 


92 


261 
196 
208 
123 


190 
190 
123 

103 
83 
73 

63 
45 
48 

42 
37 
37 

55 
42 
51 


262 
339 
257 
IGO 


215 
231 
105 

113 
117 
93 

90 
77 

66 

80 
60 
56 

55 
56 
52 


328 
360 
352 
122 


299 
235 
219 

109 
157 
148 

135 
111 
104 

101 
85 
77 

98 
88 
96 


*  From  experiments  made  at  Boulogne-sur-mer  hy  Engineer  Yoisin,  published 
in  **  Annales  des  Fonts  et  Chaussees"  for  1858. 


252 


PRACTICAL  TREATISE  ON  LIMES, 


Table  XYIII  shows  the  resistance  of  prisms  of  concrete  made 
with  the  natural  Portland  cement  of  Boulogne- 
sur-mer.  The  prisms  were  5.9056  inches 
square  in  cross  section,  and  were  broken  by  a 
load  at  the  middle,  while  resting  on  supports 


Strength  of  con- 
cretes of  natural 
Boulogne  Port- 
land cement. 


Id} 


a 


31.496  inches  apart.    The  formula  W  =  f  R   wasused 

in  deducing  the  values  of  R.    (See  paragraph  554.) 


499.  TABLE  XIX. 

GIVINa  TEIALS  MADE  AT  FORT  ADAMS,  R.  I.,  BY  GENERAL  TOTTEN,  IN  JUNE,  JULY, 
AND  AUGUST,  ISST,  OF  THE  STRENGTH  OF  CONCRETES  MADE  IN  DECEMBER,  1836. 


Composition  of  the 
mortars. 


Granite  fragments 
with  1  measure  of 
mortar. 

Granite  fragments  ^ 
with  2  measures 
of  mortar. 

Brick  fragments 
with  1  measure  of 
mortar. 

Brick  fragments 
Avith  2  measures 
of  mortar. 

Stone  gravel  witli  1 
measure  of  mor- 
tar. 

Stone  gravel  with  2 
measures  of  mor- 
tar. 

Brick  gravel  with  1 
measure  of  mor- 
tar. 


Brick  gravel  with  2 
measures  of  mor 
tar. 

Stone  fragments 
grouted. 

Brick  fragments 
grouted. 


E  = 


R  = 


R  = 


R  = 


R  = 


R  ^ 


Cement,  1.00 

Sand  0 

Lime  0 

Cement,  1.00 

Sand  50 

Lime  0 

Cement,  1.00 

Sand  50 

Lime  25 

!  Cement,  1.00 
Sand.... 1.00 
Lime  0 

i  Cement,  1.00 
Sand....  1.00 
Lime.  .  .  .25 

Cement,  1.00 
Sand....  1.50 
Lime    ..  .0 

Cement,  1.00 
Sand....  1.50 

Lime  25 

o  o  • 

r-(ci 
"fl     •  • 

g  s  s 

Cement,  1.00 
Sand....  2.00 
Lime  25 

4973 

4142 

2778 

3989 

2721 

2045 

2056 

lost 

1574 

311 

260 

174 

251 

171 

129 

130 

99 

4068 

4983 

5064 

4088 

5366 

1547 

8537 

1643 

1972 

255 

312 

317 

313 

336 

3242 

2117 

4127 

3254 

1788 

2136 

1567 

3649 

204 

133 

259 

205 

113 

134 

98 

229 

2S05 

5047 

2826 

4232 

1178 

3655 

3856 

2320 

4803 

1T6 

316 

277 

265 

74 

229 

242 

146 

301 

1097 

1049 
66 

1240 
78 

1256 
79 

1066 
67 

2347 

4247 

2655 

1295 

3351 

147 

267 

167 

82 

210 

5437 

6183 

3088 

lost. 

4726 

341 

887 

194 

296 

6025 

5712 

5480 

8142 

2699 

377 

358 

343 

197 

169 

3278 

1846 

2012 

1158 

117S 

206 

116 

127 

73 

74 

1634 

2305 

2869 

2726 

2770 

103 

145 

180 

171 

111 

The  results  given  in  the  above  table  show  the  weight  in 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


253 


pounds  required  to  break  prisms  of  concrete,  12"  x  6"  x  0"  the 
distance  between  the  supports  being  9  inches.  In  tlie  table, 
one  measure  of  mortar  corresponds  to  the  vokime  of  voids  in  the 
granite,  or  brick  fragments  used,  and  two  measures  to  twice 
that  vobime.  Tlie  values  of  R  are  computed  for  this  work 
from  the  formula,  paragraph  55i.  The  cement  was  from  Ulster 
county,  I^ew  York,  and  the  lime  from  Fort  Adams,  and  was 
very  slightly  hydraulic.  The  volume  of  voids  in  the  granite 
and  brick  fragments  was  .48  and  in  the  stone  and  brick  frag- 
ments .39.  The  lime  paste  was  passed  through  a  paint  mill 
just  before  using  it,  and  the  coarse  fragments  were  drench- 
ed with  water  just  before  mixing  them  with  the  mortar. 

500.  The  quay  walls  and  certain  parts  of  the  Mole  of  Al- 

jjiers,  as  described  by  M.  Poirel  in  "Memoires 

.     m  V  -,  I    M    1        Mole  of  Algiers, 

sur  les  iravaux  a  la  mer,   1841,  were  built  by 

pouring  and  ramming  concrete  into  caissons,  sunk  in  position, 
and  lined  with  tarred  cloth,  a  system  borrowed  from  the  Italian 
engineers,  who  repair  breeches  in  walls  by  casting  down  bags 
of  concrete,  from  which  the  mortar  exudes  in  sufficient  quan- 
tity to  bind  the  whole  together.  M.  Poirel  also  employed 
concrete  as  artificial  blocks  of  360  cubic  feet  each,  weighing  22 
tons,  formed  and  allow^ed  to  set  in  wooden  moulds  in  the 
air 

For  concrete  immersed  green,  the  mortar  was  composed  as 
follows  :  paste  of  fat  lime,  one  volume  ;  powdered  j)ozzuolana, 
two  volumes. 

The  mortar  for  forming  the  artificial  concrete  blocks  in  the 
air  was  composed  of :  paste  of  fat  lime,  1 ;  powdered  pozzuo- 
lana,  1  ;  sand  1. 

In  both  cases,  one  volume  of  the  mortar  mixed  with  one 
volume  of  broken  stone,  gave  one  volume  of  concrete  in  place. 

The  pozzuolana  which  succeeded  best  was  the  Roman,  and 
it  was  used  in  the  state  of  fine  powder,  being,  in  fact,  quite 
inert  if  left  in  coarse  grains,  like  sea-sand. 

501.  In  executing  the  new  Graving  Dock,  'Ro.  3,  at  Toulon, 


254 


PR  AC  l  ie  AL  TREATISE  ON  LIMES, 


Graving  Dock,  M.  Noel,  the  engineer,  adopted  a  concrete  foun 
o.  3,  at  Toulon.  elation,  laid  under  water  while  green.  It  was 
400  feet  long,  100  feet  wide,  with  an  average  thickness  of  15 
feet,  all  in  one  mass.  This  area  was  first  enclosed  on  three 
sides  with  close  piling,  lined  on  the  inside  with  tarred  canvas. 
Having  thus  prepared  a  solid  foundation  at  the  requisite  level, 
the  concrete  hearting  of  the  side,  head,  and  gate  walls  of  the 
dock  was  laid  under  water  in  caissons  of  appropriate  dimen- 
sions, leaving  nothing  but  a  lining  or  revetment  of  masonry  to 
complete  these  walls.  The  total  quantity  of  concrete  was 
554,300  cubic  feet  in  the  bottom,  and  418,600  cubic  feet  in  the 
sides.  The  mortar  of  this  concrete  was  composed  of  one  vol- 
ume of  paste  of  fat  lime,  and  two  volumes  of  finely  pulverized 
Italian  pozzuolana. 

502.  At  Marseilles,  M.  Pascal  made  use  of  immense  blocks 
Jetties  at  Mar-  concrete,  allowed  to  harden  in  the  air  three 
seilies.  months  before  immersion,  for  the  protection  of 
the  outer  or  seaward  slopes  of  the  jetties,  which  enclosed  the 
basins  and  docks  of  that  harbor.  The  concrete  blocks  weio^hed 
about  22  tons  each,  and  were  formed  in  moulds  of  353  cubic 
feet  capacity. 

The  mortar  was  composed  of  three  parts  of  Theil  hydraulic 
lime  slaked  by  immersion  and  measured  in  powder,  and  five 
parts  of  sand  ;  for  a  more  active  mortar,  one-third  of  the  lime 
was  replaced  by  an  equal  quantity  of  Italian  pozzuolana.  One 
volume  of  this  mortar  was  mixed  w^ith  two  parts  of  broken 
stone.  For  concrete  to  be  immersed  immediately,  two  volumes 
of  mortar  to  three  volumes  of  broken  stone  were  used. 

503.  M.  Pascal  expressed  his  preference  for  good  hydraulic 
lime,  over  any  pozzuolana  mixture,  or  any  natural  or  artificial 
cements,  provided  plenty  of  time  could  be  allowed  to  harden 
before  immersion. 

504.  The  Cherbourg  breakwater  is  composed  of  a  hearting  of 
rubble,  d  pierre perdue^  upon  which  rests,  at  the  level  of  ordi- 
nary low  water,  a  bed  of  concrete  seven  feet  thick,  composed 


IIYDKAULIO  CEMENTS,  AND  MORTAKP  25^ 

of  lime  mortar  and  broken  stone.  The  parapet  resting  on  this 
platform  is  thirty  feet  wide  at  the  base  and  thirtv-one  feet  high 
towards  the  sea. 

Recently  it  was  found  necessary  to  protect  the  exposed  base 
of  the  wall  seaward  by  huge  artificial  blocks  capable  by  their 
inertia  of  resisting  the  waves  of  the  Atlantic.  These  blocks 
contained  720  cubic  feet  each,  and  weighed  forty-four  tons,  and 
were  formed  by  rubble  masonry,  built  up  by  hand  on  platforms, 
in  positions  subjecting  them  to  submersion  at  each  returning 
tide. 

The  stone  used  was  mostly  the  schistous  rock  of  the  neighbor- 
hood, and  the  mortar  was  composed  of  either  Parker's  or  Me- 
dina cement  and  sand,  or  Portland  cement  and  sand.  The 
three  cements  were  sometimes  mixed  together.  The  propor- 
tions were  one  volume  of  Parker's  or  Medina  cement  to  one 
and  a  half  of  sand,  or  one  volume  of  Portland  cement  to 
two  of  sand,  or  intermediate  proportions,  when  the  cements 
were  mixed  together. 

Rubble  masonry  was  preferred  to  concrete  for  these  blocks, 
as  no  wooden  moulds  were  required.  These  blocks  have  satis- 
factorily withstood  the  action  of  the  waves  for  fourteen  years. 

505.  At  Dover  and  at  Alderney  hrealcwaters  Portland 
cement  has  been  extensively  used  in  forming  artificial  blocks 
which  were  laid  in  the  jetties  instead  of  blocks  of  ashlar.  The 
jetties  have  ashlar  facings  or  revetments.  The  blocks  of  con- 
crete at  Dover  were  composed  of — 

1  vol.  Portland  cement, 

2  "    Coarse  shingle. 
2   "   Fine  " 

2   "  Sand, 

4  "    Spalls  of  the  Island  stone, 

Mixed  together  in  a  box  which  revolves  eccentrically.  The 
concrete  blocks  were  made  in  moulds,  in  which  they  were  allow- 
ed to  harden  eight  or  ten  days,  and  were  then  subjected  to  two 
or  three  months'  exposure,  before  submersion  by  the  aid  of  a 
diving-bell 


256 


PRACTICAL  TREATISE  ON  LIMES, 


At  Alderney,  tlie  concrete  is  composed  of — 

1  part  Portland  cement, 

2  "  Sand. 

4    "  Shingle, 

Formed  in  moulds  into  which  irregular  masses  of  rubble,  to  the 
extent  of  thirty-eight  or  forty  per  cent,  of  the  whole,  are  rammed. 
Some  lime-blocks  which  were  used  there  were  composed  of — 

2  parts  Coarse  shingle. 
2    "     Fine  " 

1  »  Sand, 

2  "     Spalls  of  the  Island  stone. 
1  part  pound  Aberthaw  lime. 

The  cement  blocks  are  tested  by  lifting  them  four  days  after 
they  are  made,  and  the  lime-blocks  eight  days  after. 

At  these  ages  respectively  they  were  required  to  sustain  their 
own  weight.  For  handling  the  blocks,  two  pieces  of  stone 
around  which  the  concrete  is  rammed,  are  introduced  into  each. 
These  stones  act  as  a  dovetail,  being  broader  at  the  bottom 
than  at  the  top,  and  have  lewis  holes  in  them.  The  cement 
blocks  were  required  to  be  two  months  old,  and  the  lime-blocks 
four  months  in  summer  and  six  in  winter,  before  they  were 
placed  in  the  works. 

Two  cubic  yards  of  cement-concrete  required  five  and  a  half 
bushels  of  dry  cement,  and  the  same  quantity  of  the  lime-con- 
crete required  six  and  one-eighth  cwt.  of  blue  Lias  or  Aber- 
thaw lime. 

500.  In  the  United  States  concrete  has  for  many  years  been 
very  extensively  employed  in  the  construction  of  the  civil  and 
military  public  works  of  the  country,  and  recently  in  the  foun- 
dations and  even  the  exterior  and  partition  walls  of  private 
residences  and  factories. 


HYDRAULIC  CEMENTS,  AND  MOETARS.  257 


501.  TABLE  XX. 

SHOWING  THE  COST  OF  VARIOUS  KINDS  OP  MASONRY  PER  CUBIC  YARD,  AND  THE 
VOLUMES  OF  MORTAR  REQUIRED  FOR  EACH. 


■is 

«  3 

g  9 

ween 
ment 
ison- 
rtar. 

Cost  per  cubic 

1 

lira 

10  CG 

<x>  o 
W  G 

1-  fl  2 
<v  o  a  a 

yard  qf  masonry 
laid  in. 

Kind  of  masonry. 

ntity 
lired  i 
used. 

a 
B 

o 

■H  a  §  t*^ 

if 

I 

C3  u  to 

5  H  w 

li 

a 

q 

ub.  ft. 

DDIS. 

bbls. 

$  c. 

$  c. 

$  c. 

Rough  masonry  in  rubble  stone, " 

or  the  refuse  of  quarries  called 
"  grout,"  from  |  to  -^g  cubic  ft.  in 

- 

ins 

.565 

.90 

4.10 

5.00 

volume. 

Ordinary  masonry  in  blocks,  large ' 

and  small,  not  in  courses,  with 
their  joints  rough  hammer  dress- 

ft 1 
o.  1 

.423 

7.00 

7.62 

ed. 

Masonr}'-  in  large  masses,  headers' 

and  stretchers  dovetailed,  as  or- 

dinarily used  for  facing  sea-walls, 

LO 

.05 

.11 

.08 

9.00 

9.08 

sustaining  walls,  good  hammer- 
dressed  beds  and  joints  kept  full. 

Ordinary  masonry  in  courses  of  20 
in.  to  32  in.  rise. 

1.5 

.08 

.IT 

.12 

5.70 

Ordinary  masonry  in  courses  of  12 
in.  to  20  in.  rise. 

2.0 

.105 

.22 

.16 

2.19 

8.0 

.42 

.90 

.66 

5.70 

6.40 

Concrete  (the  vol.  of  voids  in  the 

coarse  fragments  being  about  .30.) 

of  good  quality, . 
of  medium  " 

ILO* 

.54 

L75 

1.21 

2.19f 

3.40+ 

9.0* 

.41 

1.06 

.65 

1.56i 

2.2lt 

of  inferior  *' 

8.0* 

.37 

.97 

.60 

1.45§ 

2.05§ 

Rubble  masonry,  dry  (i.  e.  without  ) 

.^.00  to  3.30 

The  cost  of  materials  delivered  at  the  work  has  been  assumed 
to  be  as  follows  :  cement,  $1.20  per  barrel ;  lime,  $1.00 ;  bricks, 
$4.25  per  thousand ;  sand  and  gravel,  80  cents  per  ton  ;  granite 
fragments  produced  from  stone-cutters'  chips,  at  55  cents  per 


Remarks  on  Table  XX. 
*  These  mortars  are  not  exactly  identical  in  the  proportion  of  paste  and  sand, 
t  Coarse  ingredients  entirely  of  granite. 
X  Coarse  in<;n'f'dieuts  entirely  of  gravel. 
§  Coarse  ingredients  entirely  of  gravel. 

Note  io  Second  Ediiion.—^Nith  cement  at  $2.50  per  barrel,  lime  at  $2.00,  labor 
at  $1.50  per  day,  and  sand  close  at  hand,  good  concrete  is  estimated  at  $6.00 
per  cubic  yard.— Q.  A.  G. 

17 


258 


PRACTICAL  TREATISE  ON  LIMES, 


cubic  yard,  neglecting  the  cost  of  stock ;  labor,  $1.00  per  day, 
and  the  necessary  superintendence.  The  work  is  supposed  to 
be  of  some  extent,  and  the  operations  to  continue  without  inter- 
ruption through  the  season. 

For  walls  under  two  feet  in  thickness,  the  prices  in  the  table 
will  be  increased  somewhat.  The  rate  of  increase  for  thin  hol- 
low concrete  walls,  which  require  movable  boxing  on  both 
faces,  will  probably  reach  but  not  exceed  10  per  cent.,  while 
for  the  other  kinds  of  masonry  the  increase  of  expense  will  be 
more  moderate. 


HYDBA.ULIC  CEMENTS.  AND  MORTARS. 


259 


CHAPTER  YHI. 


508.  Iisr  a  memoir  submitted  to  the  French  Academy  of  Sci- 
ences in  the  year  1856,  entitled  "  General  Considerations  upon 
Hydraulic  Materials  used  for  Constructions 

in  the  Ocean,"  to  which  reference  is  made  in  SnefandEivot. 
other  parts  of  this  work,  the  authors,  MM. 
Chatoney  and  Rivot,  Engineers  of  Roads  and  Bridges,  are  led, 
as  the  results  of  their  experiments,  to  some  deductions  some- 
what at  variance  with  the  established  usage  of  European  engi- 
neers. As  many  of  the  points  to  which  they  direct  special 
attention  can  have  no  practical  interest  to  American  engineers, 
they  will  not  be  noticed  here. 

509.  From  page  159  of  their  memoir  we  quote  as  follows : 

"  We  have  supposed  until  now,  that  the  cements  should  be 

tempered  with  a  quantity  of  water  just  sufficient  to  obtain  the 

consistency  requisite  for  workiner  it :  but,  when- 

,  ,        .    .  °  They  recommend 

ever  it  is  possible,  it  is  better  to  use  pure  ce-    pure  cement  to 

,    .  '  xi   '  J         j*^'  •  'i-i         be  used  with  an 

ment  m  a  semi-nuid  condition,  viz. :  with  a    excess  of  water. 

great  surplus  of  water ;  in  becoming  solid,  it  j 
rejects  the  water  not  necessary  for  hydration,  and  its«texture  is 
much  more  compact  than  when  tempered  to  ordinary  consis- 
tency ;  it  may  be  said  that  the  molecules,  left  to  themselves  in 
a  more  liquid  medium,  arrange  themselves  better ;  they  are 
more  watery  and  carry  Jess  air  with  them ;  for  this  double  reason 
the  mortars  are  less  porous." 

510.  M.  Yicat  arrays  himself  against  what  he  terms  this  new 


260 


PEAOTICAL  TREATISE  ON  LIMES, 


doctrine,  and  pertinently  asks  how  it  is  possible 
^is^doctrine.^'*^^  ^^^^  augmentation  of  volume,  due  to  a  sur- 

plus of  water,  can  be  attended  with  an  increase 
of  density,  when  the  mortars  have  attained  their  final  harden- 
ing. That  skilful  experimenter  at  once  set  to  work  in  his  labor- 
atory to  disprove  this  statement  of  MM.  Chatoney  and  Eivot. 
For  this  purpose,  glass  tubes  of  equal  diameters  (nearly  two  in- 
ches) were  procured,  and  into  them  were  introduced,  respective- 
ly, the  several  natural  cements  from  Grenoble,  Paris,  Yassy,  and 
La  Valentine,  mixed  in  one  case,  in  the  proportion  of  50  parts 
of  water  to  100  parts  of  cement,  and  in  another  in  the  propor- 
tion of  120  parts  of  water  to  100  of  cement.  The  pastes  were 
stirred  with  a  glass  rod  until  they  began  to  stiffen.  The  tubes 
being  of  equal  diameters,  the  volumes  of  the  several  pastes 
were  directly  proportional  to  their  altitudes  in  the  tubes. 

At  the  expiration  of  two  months,  the  glass  tubes  were  care- 
fully broken,  the  cement  cylinders  removed,  and  their  relative 
hardness,  weight,  and  capacity  of  imbibing  water  obtained, 
with  the  following  results  : 


TABLE  XXL 


No. 


Condition  of  the  paste. 


Hardness 


Weight. 


Capacity  of 
imbibition. 


For  the  stiff  paste,  after  naturally  drying 
in  the  air, 

For  the  diluted  paste,  after  naturally  drying  ) 
in  the  air,  ) 


1.000 
.016 


1.000 
.375 


1.000 
2.570 


511.  The  experiment  was  pushed  further  in  the  followmg 
manner.  The  semi-fluid  condition  of  the  paste  favored  a  subsi- 
dence of  the  heavier  particles,  which  caused  greater  density  at 
the  bottom  than  at  the  top  of  the  tube.  Other  cylinders  were 
formed  by  pouring  in  the  paste,  and  allowing  it  to  assume  a 
state  of  rest,  and  subsequently  to  harden  without  agitation. 
The  relative  hardness  as  indicated  by  the  penetration  of  the 


HYDRAULIC  CEMENTS,  AND  MORTARS.  261 

point  was  then  obtained  at  the  top  and  bottom  of  the  cylin- 
ders, with  the  following  results  ; 


TABLE  XXIL 

No. 

Condition  of  the  paste. 

Hardness  as  measured  by 
the  penetration  of  a  pomt 

1 
2 

3 
4 

Valentine  cement  tempered  to  a  good  consistency.  | 

Same,  precipitated  spontaneously  from  a  semi-  j 
fluid  mixture.  ( 

Grenoble  cement  tempered  to  a  good  consistency,  -j 

Same,  precipitated  spontaneously  from  a  semi-  j 
fluid  mixture.  ( 

Top  of  cylinder, 
Bottom  of  do. 
Top  of  do, 
Bottom  of  do. 
Top  of  do. 
Bottom  of  do. 
Top  of  da. 
Bottom  of  do. 

21 
21 

00 

05 

33 

33 

Oli 

09 

512.  The  results  given  above  were  obtained  with  what  are 
generally  termed  quick-setting  cements.  When  mixed  to  a 
stiff  paste,  they  will  set  in  twenty  to  thirty  minutes.  Similar 
trials  were  made,  and  similar  results  obtained 

.  T  i.      i?   •  p    •  J       T         i.'  M.  Vicat  and  In- 

with  cements  ot  interior  hydraulic  activity,  spector-General 

that  required  two  to  three  hours  to  set.    M.    Reibeil's expen- 

^  ence. 

Yicat  concludes,  therefore,  that  a  large  dose  of 
water  invariably  injures  cement  mortar.  Inspector-General 
Heibell,  who  used  the  Boulogne  cement  made  from  the  septaria, 
in  1852,  for  the  works  at  Cherbourg,  found  that  it  did  not 
harden  between  the  stones  when  employed  in  a  semi-fluid 
state  (en  coulis).  Some  of  this  cement  was  forwarded  to  M. 
\ricat  by  the  Inspector-General  for  trial,  and  gave  the  follow 
ing  results  after  ninety  days  immersion  : 


TABLE  XXIIL 

No. 

Condition  of  the  paste. 

Tenacity  per  sq. 

centimetre, 
(.3937"  X. 3937") 

1 

2 
3 

For  100  parts  Boulogne  cement  tempered  with  50  parts  water, 
U   ;^00     "            *'            "            "            "    57      "  " 
"  100    "          "          »          "          "    80     »  " 

8.20  kilograms. 
6.45  " 
3.75  " 

These  results,  says  M.  Vicat,  were  found  to  correspond  with 
those  obtained  at  Cherbourg. 


262 


PEACTICAL  TEEATISE  ON  LIMES, 


513.  There  is,,  perhaps,  little  doubt  that  the 
^rthte^T^aSe^^  ^^^ults  reported  by  M.  Yicat  are,  in  the  main, 
correct,  although  much  depends  on  the  age  of 
the  cement,  and  the  manner  of  its  preservation  ;  newly-made 
cement  takes  a  much  firmer  consistency  with  a  given  quantity 
of  water,  than  that  in  which  the  uncombined  quicklime  has  be- 
come spontaneously  slaked. 

514.  The  trials  with  tubes  were  greatly  exaggerated^  and  fur- 
nish no  conclusive  refutation  of  the  deductions  of  M.  Chatoney, 
for  that  engineer  recommends  for  his  thin  paste  four  parts  of 
water  to  ten  of  cement,  while  M.  Yicat  used  with  the  same 
quantity  of  cement  five  parts  of  water  to  obtain  his  maximum 
consistency,  and  twelve  parts  for  the  minimum,  being  an  excess 
of  water  equal,  in  the  two  cases  respectively,  to  25  per  cent., 
and  300  per  cent,  over  the  maximum  quantity  adopted  by  M. 
Chatoney. 

515.  It  will  be  seen  that  M.  Yicat  made  his  trials  with  the 

natural  cements;  M.  Chatoney,  on  the  other 
ment  used  en        hand,  had  reference  to  the  "  Portland"  cement 

which  had  been  used  by  him  "  to  stop  the  infil- 
trations of  water  under  the  cut  stone  of  the  apron  of  the  Florida 
Dock,  at  Havre,"  the  beton  on  which  the  apron  rested  having 
become  so  decomposed  under  the  influence  of  sea-water  that 
the  pebbles  were  no  longer  bound  together  by  the  mortar. 
The  following  preliminary  experiment  was  made :  A  box 
about  six  and  a  half  feet  long,  two  and  a  quarter  feet  wide,  and 
four  inches  deep  was  filled  with  the  pebbles  used  for  concrete, 
and  covered  up  with  a  board  well  loaded  down  with  weights. 
Into  one  of  the  corners  of  this  box  was  then  poured  through  a 
vertical  tube  1.57  inches  in  diameter,  and  17  feet  four  inches 
high  a  mixture  of  five  parts  of  Portland  cement  and  two  parts 
of  water."^    M.  Chatoney  says :    "  When  the  box  was  taken  to 


*  Some  blocks  of  concrete,  noticed  in  another  part  of  this  work,  were  made  in  this 
manner  on  Governor's  Island,  New  York,  in  the  autumn  of  1860. 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


263 


pieces  the  cement  was  found  to  have  penetrated  among  the  peb- 
bles to  the  extremities  of  the  box,  and  had  transformed  them  into 
excellent  beton,  more  compact  than  could  have  been  made  by 
masons  upon  a  stand."  This  experiment  was  deemed  so  satis- 
factory that  the  infiltrations  under  the  dock-apron  were  stopped 
by  an  injection  of  liquid  paste  of  Portland  cement.  Some  of 
this  cement,  which,  after  completely  filling  the  vacant  spaces, 
had  overflowed  the  apron,  and  attached  itself  firmly  to  the  cut- 
stone,  was  removed  and  kept  in  sea- water  for  testing.  It  fur- 
nished the  following  results : 

516.  TABLE  XXIY. 

Giving  the  tractile  strength  of  mortars  of  pure  Portland  cement 
mixed  to  a  cream  with  two-fifths  of  its  volume  of  water,  injected 
into  and  kept  in  sea- water : 


Age  of 
mortar. 

Weight  required  to  break  the  prisms  by  a  force  of  extension. 

15  days, 
45  " 
135  " 

134|-  pounds  per  square  inch. 
207^     "      "  " 
233i     «      "  " 

517.  It  is  claimed  for  the  Portland  cement  by  those  who 
have  given  the  subject  attention,  and  are  acquainted  with  its 

use,  that  however  favorably  it  may  compare 

.11,  T  ^  ,  AUeged  superi- 

with  the  best  natural  cements  oi  JliUrope,  when  ority  of  Port- 
employed  as  a  stiti*  mortar, — and  experiments 
appear  to  establish  its  superiority  with  singular  unanimity, — 
its  most  prominent  and  valuable  properties  are  displayed  when 
employed  under  conditions  similar  to  those  which  obtained  at 
Havre,  that  is,  when  mixed  with  a  surplus  of  water,  capable  of 
producing  a  semi-fluid  ^r  creamy  consistency  {en  coulis). 
When  thus  treated,  it  sets  rather  slowly,  some  varieties  retain- 
ing the  plastic  condition  for  hours  ;  and  while  hardening,  it  is 
said  to  reject  a  portion  of  the  excess  of  water. 


264 


PEACTICAL  TREATISE  ON  LIMES, 


518.  The  deductions  of  M.  Yicat  in  the  laboratory  from  tri- 
als with  the  natural  cements  of  Grenoble,  Paris, 


way,  must  therefore  be  received  with  some  can- 
tion,  when  we  attempt  to  compare  them  with  practical  results, 
obtained  with  a  cement  produced,  as  the  "  Portland"  is,  under 
the  peculiar  condition  of  a  vitrifying  heat. 

519.  It  does  not  appear  that  any  trials  of  strength  were 
made  with  concrete  formed  by  the  process  of  injection,  prac- 
tised by  M.  Chatoney.  Compared  with  the  resisting  power  of 
the  cementing  substance  itself  mixed  with  an  excess  of  water, 
such  concretes  must  be  strong,  as  the  conditions  are  peculiarly 
favorable  to  the  development  of  the  adhesive  properties  of  the 
cement.* 

*M.  Yaudrey,  Engineer  des  "  Fonts  et  Chaussees,"  who  succeeded  M.  Darcel  in 
the  service  of  the  Seine  Navigation  and  Paris  Bridges,  made  use  of  the  natural  Bou- 
logne "Portland"  cement  in  preference  to  the  Roman,  in  reconstructing  the  St. 
Michel's  Bridge  in  Paris.  A  notice  of  this  work  published  in  the  Annales  des 
Fonts  et  Chaussees  for  1857,  volume  xiv.,  furnishes  the  following  extracts : 

"  Engineers  daily  meet  with  occasions  for  using  Roman  cement,  (natural  hy- 
draulic cement).  They  acknowledge  that  great  inconveniences  arise  from  the  mor- 
tars setting  much  too  rapidly,  which  renders  it  necessary  to  prepare  it  in  smal 
quantities  at  a  time.  The  proportion  of  cement  used  generally  renders  these  mor- 
tars very  expensive.  With  '  Portland'  cement,  the  mortar  can  be  made  up  in  small 
quantities  and  by  the  most  economical  process,  as  the  setting  begins  only  aftei 
eight  hours.  The  workmen  consequently  have  the  time  necessary  for  using  the 
mortar.  Moreover  with  a  much  smaller  percentage,  the  '  Portland'  produces  a  more 
resisting  mortar  than  the  Roman  cement."  In  reconstructing  the  St.  Michel's 
bridge,  a  portion  of  the  old  masonry  that  had  stood  for  two  centuries,  was  left  in  the 
buttresses.    For  the  new  masonry  of  these  buttresses  the  mortar  was  composed  of — 


In  its  fabrication,  the  sand  and  cement  were  first  mixed  dry,  the  water  being 
added  after  these  two  substances  had  become  thoroughly  incorporated.  Its  amount 
necessarily  varied  with  the  state  of  dampness  of  the  sand ;  it  was  on  the  average ; 
126  litres  (132.1  quarts)  water  for  1  cubic  metre  (1.3  cubic  yard)  of  sand. 

The  analysis  of  the  cost  is : 


1  cubic  metre  (1.3  cubic  yard)  of  river  sand, 

250  kilogrammes  (550  lbs.  avoir.)  of  Portland  cement. 


For  1  cubic  metre  of  sand  

250  kil.  Portland  cement  (at  Fr.  .08  per  kil.) 
Cost  of  fabrication  


Fr.  3.20 
20.00 
2.50 


Price  of  one  cubic  metre  of  mortar 
(Which  is  equal  to  $3.64  per  cubic  yard). 


Fr.  25.70 


HYDRAULIC  CEMENTS,  AND  MORTAES.  265 


520.  This  seems  a  suitable  place  to  introduce  the  results  ob- 
tained with  some  American  cements,  mixed  to    Trials  of  Ameri- 
difierent  degrees  of  consistency.    These  are    can  cements, 
given  in  the  following  table  : 

TABLE  XXY. 

Showing  the  ultimate  strength  of  rectangular  parallelopipeds 
of  pure  cement  mortar,  2''  X  2"  X  8"  formed  in  vertical 
moulds  under  varying  conditions  of  consistency  and  compres- 
sion, and  broken  on  supports  four  inches  apart,  by  a  pressure 
from  above,  midway  between  the  supports.  The  mortars  were 
kept  in  a  damp  place  twenty-four  hours,  and  were  then  im- 
mersed and  kept  in  salt  water  until  broken.  The  numbers 
from  1  to  23,  inclusive,  were  59  days  old  ;  those  from  24  to  59, 
inclusive,  were  320  days  old. 

"  According  to  the  specifications  of  the  contract,  the  mortar  of  cement  made  in 
the  proportion  of  3  vol.  of  sand  for  1  vol.  of  cement,  and  moulded  into  prisms  .04 
metre  x  .04  metre  (1.57  in.  x  1.57  in.),  and  immediately  deposited  in  water  must,  al 
the  end  of  eight  days,  resist,  vv^ithout  breaking,  the  tractile  strain  of  40  kilogr. 
(88.16  pounds).  This  clause  at  once  excludes  the  Roman  cements,  which,  under 
these  conditions,  break  under  the  tractile  strain  of  12  to  15  kilogr.  (2G^  to  33 
pounds)."  "The  Boulogne,  'Portland'  cement  generally  bears  80  kilogr.  (176.33 
pounds).  It  weighs  about  1.100  kilogr.  (2.425  pounds)  per  cubic  metre.  (68|-  pounds 
per  cubic  foot)." 

"The  proportion  of  250  kilogr.  of  cement  for  one  cubic  metre  of  sand  corre- 
sponds to  a  quantity  of  cement  less  than  one  fourth  that  of  the  sand." 

"The  prisms  bear  after  eight  days  a  weight  of  30  kilogr.  (6G.1  pounds).  This 
cement  was  manufactured  by  MM.  Demarle  &  Co.  of  Boulogne-sur-mer  (see  par- 
agraph 87)  who  delivered  it  to  the  works  in  Pai'is  for  eight  francs  per  hundred  kil- 
ogrammes (67  cents  per  hundred  pounds)." 

Mr.  Vaudrey  further  remarks  :  "  When  the  Roman  cements  first  appeared  in  the 
market,  tlieir  price  was  far  from  being  so  reasonable  ;  I  firmly  believe  that  the  price 
of  the  *  Portland'  cement  will  be  considerably  reduced  after  some  time.  A  great 
many  localities  possess  the  elements  necessary  for  the  manufacturing  of  that 
cement.  I  shall  mention,  among  them,  the  layers  of  marl  above  those  of  gypsum 
at  the  Buttes  Chaumont  where  some  hydraulic  lime  and  Roman  cement  are  already 
manufactured.  However,  for  the  '  Portland'  cement,  a  precise  proportion  of  21  pei 
cent,  of  clay  is  necessary. 

"  The  calcination  is  a  very  important  element  in  the  manufacturing  of  all  cements; 
the  less  calcined  they  are,  the  quicker  they  set ;  but  in  proportion  as  they  sefc 
quickly,  their  power  of  resistance  diminishes.  I  have  no  confidence  in  very  quick- 
setting  cements." 


266 


PEACTICAL  TEEATISE  ON  LIMES, 


Kind  of  cement. 


CompoBition  of  the  mortar. 


Penetra- 
tion of 
point  in 
in  inches. 


James  River . 


4  vol.  dry  cement.  J  j  A  thick  cream  poured 
-  t<  mto  moulds  and  shaken 

'  ( down. 


4  vol.  dry  cement.  |  .  ctiff  nast^ 
vol.  water.     f  ^       P^^*®  • 


A  stiflF  paste  well  shaken 
in  moulds  and  rammed. 


4  vol. 
2  vol. 


dry  cement 
water. 


Paste  rather  thin,  shak- 
en in  moulds,  and 
rammed. 


{Roscndale, 
Holfman 
Brand, 


/  Eosendale, 
■I  Delafie.ld»& 
(  Baxter. 


Pure  cement  and  water,  a  thin  paste  

il           (I  i( 

"  a  stiff  paste  

"           u  u            .  v.  .  . 

"        "  a  thin  paste  

"        "  a  very  thin  paste 

"         "  a  thin  paste  

((                U  kk 

l(  u 

u             u  " 

"        "  a  stiff  paste  

"        "  a  thin  paste  

u            u  " 

"        "  a  very  thin  paste 

i(                U  (•(• 

u              n  't  " 

u  "            "  * 

U             tl  «           "  * 

*'        "  a  stiff  paste  


none 

.175 

.277 

248" 

.197 

.297 

236 

.290 

.410 

346 

.300 

.420 

291  ■ 

.330 

split 

291 

II 

.330 

split 

299 

.300 

split 

275 

.300 

.400 

267, 

32  lbs. 

.075 

,125 

510" 

.090 

.145 

447 



— 

557  " 

.122 

1S5 

557 

.140 

.216 

416. 

none 

.180 

.260 

322 1 

.167 

.252 

291  1 

.190 

283  j 

.180 

.250 

259  J 

split 



22S"! 

split 

— 

252 

.240 

.850 

259  ■ 

.250 

.300 

291 

.250 

.350 

232 

(.1 

.230 

.330 

24:3 

32  lbs. 

.060 

.100 

375' 

.070 

.120 

359 

.067 

.125 

441 

.067 

.116 

461 

4021 

.077 

.137 

371 

.065 

.125 

355  ■ 

.060 

.110 

425 

.057 

.137 

409  j 

none. 

.112 

.200 

648  ) 

ii 

.140 

.237 

644  ) 

a 

.122 

.227 

404  / 

" 

.102 

.190 

396  f 

32  lbs. 

.180 

.180 

7851 

.175 

.130 

769  1 

.067 

.127 

572  f 

.070 

.120 

644  J 

.064 

.114 

650  ) 

.057 

.110 

644  V 

.070 

.090 

613  ) 

.100 

.180 

621 

.110 

.200 

605 

none 

.150 

.240 

404  • 

.ISO 

.280 

401 

.150 

.240 

409 

.ISO 

.280 

413 

.177 

.277 

425 

.142 

.240 

456 

32  lbs. 

.052 

.090 

11341 

.057 

.105 

1141 

.047 

.085 

808 

.035 

.077 

795 

.050  .087 

816 

.140  .080 

8G2 

.037 1 .075 

707 

.040  .0501  707  J 

HYDRAULIC  CEMENTS,  AND  MOIITAES. 


267 


GENERAL  DEDUCTIONS  FROM  TABLE  XXV. 

let.  The  two  Rosendale  cements  offer  better  results  than 
that  from  James  River.  The  results  of  the  table  are  rather 
discrepant. 

2d.  'No  great  advantage  appears  to  be  gained  by  mixing  the 
paste  stiff,  provided  it  is  in  condition  to  set  under  compression. 
Delafield  and  Baxter's  cement  gave  much  the  best  results  when 
mixed  stiff. 

3d.  When  neither  is  subjected  to  compression  during  setting, 
a  thin  paste  produces  about  as  strong  a  mortar  as  a  stiff  one. 
ISTos.  1  to  8,  and  Nos.  14  to  17. 

4th.  Between  the  limits  of  lj\  to  2j\  vol.  of  water  to  4  of 
cement,  there  is  a  variation  of  about  13  per  cent,  in  the  average 
resistance  of  the  mortars,  the  lowest  average  resistance  corre- 
sponding to  two  vol.  of  water  to  four  of  cement.  This  result 
must  be  regarded  as  a  discrepancy  due  to  imperfect  manipula- 
tion.   JSTos.  1  to  8,  14  to  17,  and  18  to  23. 

521.  From  numerous  laboratory  experiments  Tests  of  Portland 
carried  on  at  Cherbourg,  in  order  to  test  the  cement  used  at 
quality  of  the  "  Portland  "  cements  used  in  the 
construction  of  the  breakwater,  it  was  ascertained  that  their 
average  resistance  to  a  force  of  traction  when  mixed  stiff  and 
without  sand,  and  kept  in  salt  water  45  days  was  266  lbs.  It 
was  not  customary  to  reject  any  whose  strength  did  not  exceed 
170  to  185  lbs.,  this  being  as  high  a  degree  of  resistance  as  the 
cements  manufactured  for  the  trade  generally  attained. 

522.  Table  XXYI.  contains  results  which  afford  the  means  of 
comparing  the  tractile  strength  of  the  Roman  and  artificial 
Portland  cements.    The  trials  were  made  by 

M.  Darcel,  Engineer  of  Roads  and  Bridges,  and  of  Roman  Sd*^ 
were  reported  in  the  "  Annales  "  for  the  year  ^f^^^f  Portland 
1858.  Two  varieties  of  Portland  cement,  the 
French  (natural),  and  the  English  (artificial),  and  two  of 
Roman,  the  Paris  and  the  Yassy,  were  employed.  The 
variations  in  the  two  varieties  of  the  same  article,  were  so 


268 


PEACTICAL  TREATISE  O'N  LIMES, 


slight  ill  both  cases,  that  the  differences  are  not  retained  in  the 
table.  M.  Darcel's  trials  were  made  in  the  open  air  npon 
quadrangular  prisms  of  1.57"  X  1.18"  in  cross  section.  After 
having  dried  for  six  weeks,  the  prisms  were  suspended  by  one 
extremity  supporting  at  the  other  extremity  a  plate  which  was 
loaded,  until  the  prisms  broke  by  extension." 

TABLE  XXYI. 
Giving  the  tractile  strength  per  square  inch  of  cement 
mortars  42  days  old,  kept  in  the  open  air. 


Proportion  of  sand  for  1  of  cement. 


0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

Resistance  per  square  inch,  in  lbs. 

284i 

284i 

1991 

166i 

1421 

128 

116| 

106| 

99i 

92i 

Roman  cement  

1421 

1421 

113| 

92i 

79* 

67 

57 

42| 

35i 

25A 

0 

523.  MM.  Belgrand  and  Michelot,  from  their 
experiments,  give  the  results,  found  in  the  fol- 
lowing table,  obtained  with  cement  mortars 
containing  no  sand.  The  mortars  were  kept 
immersed,  and  it  appeared  to  be  immaterial 
whether  it  was  in  sea  or  fresh  water. 

TABLE  XXVII. 


Roman  and 
natural  and  arti- 
ficial Portland 
cements  without 
sand. 


Kind  of  cement. 

Age  of  cement. 

Resistance  to  a  pulling 
strain  per  square  inch. 

1  year, 
do. 
do. 

640  to  711  pounds. 
427  to  498  " 
170  to  213  " 

524.  Those  gentlemen  also  state  that  mortars  composed  of  one 
volume  of  Boulogne  ^'Portland"  cement  and 

Alleged  superior-  j  4.  •  ^ 

ity  of  Boulogne  lour  volumes  01  sand  oiier  as  great  a  resistance 
Portland  cement.        ^j^^^^  composed  of  One  volume  of  English 


HYDRAULIC  CEMENTS,  AND  MORTARS. 


269 


Trials  of  English 
Portland  and  Ro 
man  cements  in 
New  York. 


Portland"  and  two  volumes  of  sand,  and  are  superior  to  tliose 
of  Boman  cement  without  sand.  This  comparison,  as  regards 
the  Roman  cement,  is  the  same  as  that  furnished  by  Table 
XXy.,  from  the  experiments  of  M.  Darcel. 

525.  Some  trials  made  in  New  York  City^  in  1860,  in  the 
regular  course  of  these  experiments,  upon  Eng- 
lish Portland  and  Roman  cements,  supposed  to 
be  about  three  months  old,  taken  from  well-con- 
ditioned barrels,  gave  the  resistances  shown  in 
the  following  table : 

526.  TABLE  XXYIII. 

Showing  the  ultimate  strength  of  rectangular  prisms  two 
inches  square  in  cross  section,  of  Portland  and  Roman  ce- 
ment mortars,  which  set  under  a  pressure  of  32  pounds  per 
square  inch,  broken  on  supports  four  inches  apart,  by  a  force 
applied  at  the  middle. 

The  mortars  were  mixed  quite  stifi',  and  were  kept  immersed 
in  sea-water.  The  cement  was  measured  by  volume  in  loose 
powder. 


Kind  of  cement. 


Compositioa  of  the  mortar. 


Age  of 
mortar. 


Penetration  of  point, 

*  ' 

-'^  a 

in  inches. 

G  S 

Average  br 
ing  weigh  1 
each  kind 
mortar 

1  impact. 

2  impacts. 

■r 

.032 

.077 

1,521 

j-  1,536 

.057 

.105 

1,552 

.060 

.095 

1.271 

|-  1,268 

.072 

.112 

1,255 

.057 

.090 

1,017 

.072 

.107 

884 

|-  950 

.132 

.205 

248 

.152 

.238 

286 

|-  242 

.080 
.090 

.180 
.130 

585 
585 

|-  685 

English  Portland 


English  Koman . 


Puro  cement 


vol.  cement  and  1  vol.  sand, 
1 
2 


320  days, 


527.  From  the  foregoing  we  derive  the  following  table : 

TABLE  XXIX. 
Showing  the  resistance  per  square  inch  to  a  force  of  extension, 
of  mortars  of  Roman  and  Portland  cement  deduced  from  Table 
by  the  formula  W=  |  R ^  —a' 


270 


PRACTICAL  TEEATISE  01^  LIMES, 


^  b 


Kind  of  cement. 


English  Portland. 
English  Roman  . 


Composition  of  the 
mortar. 


Pure  cement  

1  vol.  cement,  1  vol.  sand, 
1    "       "       2   "  " 
1   "       "       1   "  " 
1   "       "       1    "  " 


Age  of  mortar. 


320  days, 


20 
100 


Value  of  R,  or 
tractile  strength 
per  square  inch. 


1152  pounds. 
948  " 
713 

182  " 
439  " 


528.  Trials  were  made  (see  Table  XXX.)  with  a  sample  of 
En^rlish  Portland  cement,  not  obtained  from 

Further  trials  .  ,  .  i     .      .  i     i  i  -.    t  • 

with  English  the  lot  wliich  lurnish  the  results  recorded  in 
Portland  cement,    rp^^^^  XXYII.    The  prisms  were  made  of 

rather  stiff  mortar,  rammed  into  a  mould  but  not  pressed ; 
they  were  1"  X  1"  in  cross  section,  were  kept  in  sea-water 
270  days,  and  then  broken,  on  supports  three  inches  apart,  by 
pressure  applied  to  the  middle.  The  cement  was  measured  in 
volume  of  loose  powder.  The  table  contains  the  average  of 
many  trials.  Some  of  the  mortars  were  tested  as  many  as 
thirteen  times. 

TARLE  XXX. 


No.  of  the 
mortar. 

Composition  of  the  mortar. 

Weight,  in  pounds, 
supported  before 
breaking. 

I 

Pure  cement  paste, 

306 

2 

Cement,  volume  1.    Sand,  volume  1, 

313 

3 

u          ((     1       "        *'  2 

204 

4 

"      1.       «         "  3,' 

91 

5 

74 

6 

u            u      I         a          u  5^ 

45 

529.  The  only  American  mortars  formed  in  the  same  mould 
Trials  of  Ameri-  ^^^^^  were  used  for  the  table  just  given,  and 
can  cement.  hence  furnishing  a  fair  comparison,  were  made 

of  cement  from  layer  'No.  Kine,  at  High  Falls,  Ulster  county, 
New  York.  It  was  calcined  to  a  "cinder,"  and  then  treated 
in  all  respects  like  mortar  Ko.  One  of  the  last  table,  in  regard 
to  age,  conditions  of  submersion,  manner  of  breaking,  and 
every  other  particular.   The  results  are  given  below : 


HYDRAULIC  CEMENTS,  AKD  MORTAES. 

TABLE  XXXI. 


271 


Average 
breaking 
weight. 


Remark. — We  see  that  there  is  no  remarkable  superiority  of  strength  in  the 
mortars  of  pure  Portland  cement,  Table  XXX.,  and  similar  ones  of  American  ce- 
ment, Table  XXXI.    The  Portland  cement  may  not  have  been  as  good  as  usual. 


630.  Trials  were  made  with  Portland  and 
Roman  cements  at  the  London  Crystal  Palace 
Exhibition,  in  1851.  The  following  data  are 
taken  from  the  report  thereon  : 


Portland  and 
Roman  cements 
tried  at  London. 


1.  A  prism  of  neat  Portland  cement,  4  months  old,  4  inches  square  in  cross  sec- 
tion, on  supports  16  inches  apart,  broke  with  1,580  lbs.  at  the  centre. 

2.  A  prism  of  Roman  cement,  from  the  Harwich  stone,  same  size  as  No  1,  7 
months  old,  broke  at  380  lbs.  same  bearing.    Cement  supposed  to  be  defective. 

3.  A  prism  of  Roman  cement,  from  Sheppey  stone,  same  as  No  1,  supported 
1,100  lbs.  before  breaking. 

4.  A  prism  of  Portland  cement,  6  months  old,  2"  x  2f"  cross  section,  broke 
with  a  tractile  strain  of  2,280  lbs.  (equal  to  414^^]  lbs.  per  sq.  inch). 

5.  Two  6  in.  cubes  of  Portland  stone,  cemented  with  Portland  cement,  bore  4,500 
lbs.  tractile  strain,  when  the  hook  gave  way.    Cement  4  months  old. 

6.  Two  6  in.  cubes,  as  above,  united  with  Roman  cement,  broke  at  2,780  lbs. 
(77f  lbs.  per  sq.  inch)  when  5  months  old,  by  separating  from  the  stone,  leaving 
the  cement  perfect. 

7.  A  block  of  neat  Portland,  3|"  x  2\",  one  month  old,  tore  asunder  with  a 
weight  of  3240  lbs.  (393|  lbs.  per  sq.  inch). 


TRIALS  IN  A  HYDRAULIC  PRESS. 

8.  A  block,  all  Portland  cement,  18"  high  and  9"  x  9",  bore  a  pressure  equal 
to  108^  tons  on  the  square  foot. 

9.  A  mixture  of  1  sand  and  1  cement  bore  80  tons  per  square  foot. 

10.  do.       4  do.        1     do.     do.  80  do.         do.  do. 

11.  do.        7   do.        1    do.     do.  44^  do.         do.  do. 

12.  A  block,  all  Roman  cement,  broke  at  22^  tons. 

13.  A  mixture  of  4  sand  and  1  Roman  cement  would  not  bear  any  pressuro, 

14.  A  block  of  Portland  stone  1^"  x  1"  broke  up  at  23  cwt. 


272 


PEACTICAL  TREATISE  OIT  LIMES, 


15.  A  blor^iT  ^1  neat  cement  12"  x  2f "  deep  x  2|"  horizontally,  witli  supports 
'i\  in.  apart,  \Q»A<d-\  at  centre,  broke  with  9|-  cwt. 

16.  A  block  of  neat  cement  12"  x  2f "  deep  x  2^"  wide,  with  supports  9  inches 
apart,  scales  broke  with  25  cwt.  on  centre.  The  experiment  was  repeated,  and 
the  cement  broke  with  42  cwt. 

17.  A  block  of  1  volume  cement  and  2  volumes  fine  shingle  sand,  12"  x  2f" 
deep  X  2^"  wide,  8  inches  bearing,  broke  with  10  cwt.  on  the  centre. 

18.  A  fire-brick  beam  14  in.  wide,  9  inches  deep,  and  6  ft.  4  in.  between  the 
bearirgp,  joined  with  neat  cement,  and  loaded  uniformly  over  a  central  space  2  ft 
4  in.  long,  broke  through  tlie  bricks  in  two  places  with  a  weight  of  20f  cwt. 

19.  A  fire-brick  beam,  14"  wide  x  10"  deep,  with  5  ft.  3  in.  between  the  sup 
ports,  jointed  with  neat  cement,  and  loaded  over  a  central  space  2ft.  4  in.  long, 
broke  (through  the  bricks)  in  two  places  with  30  cwt. 

20.  Several  of  the  fragments  of  brick-work,  when  thrown  against  a  stone  with 
force,  broke  in  all  eases  through  bricks  and  not  through  the  joints. 

Note.  Experiments  made  in  England  show  that  Portland  eement  adheres  better  to  the  Port'- 
land  stone  than  to  any  other  material. 

Its  advantage  for  exterior  stucco  consists  in  its  agreeable  color  naturally,  its  power  of  resisting 
frost,  and  its  freedom  from  vegetation. 

531.  The  trials  undertaken  to  ascertain  the  adhesion  of  mor- 
,  „   .     ^         tar  to  the  solid  materials  used  in  constructions, 

Adhesion  of  mor-  ^  ^  ' 

tars  to  solid  ma-  go  to  show  that  such  experiments  involve  many 
elements  of  uncertainty,  and  require  to  be  con- 
ducted with  great  care.  The  first  tests  v^ere  with  Croton 
Point  front  bricks,  of  which  a  large  number  were  cemented  to- 
gether face  to  face,  at  right  angles  to  each  other,  as  represented 
by  Fig.  2,  paragraph  32,  and  kept  320  days.  Some  were 
wetted  with  a  sponge  every  two  or  three  days,  while  others 
were  kept  dry. 

In  tearing  the  bricks  apart,  at  the  expiration  of  the  time  spe- 
cified, it  was  found  that,  in  a  majority  of  cases,  the  surface  of 
contact  of  the  brick  and  mortar  remained  intact,  the  adhesion 
to  the  brick  overcoming  the  cohesive  strength  either  of  the 
bricks  themselves,  or  of  the  mortar  composing  joint  between 
them.  The  results,  therefore,  although  interesting  for  other 
reasons,  furnish  no  entirely  satisfactory  measure  of  the  power  of 
adhesion.  In  fact,  they  are  fair  indications  of  the  resistance 
offered  by  these  materials  to  a  force  of  traction,  and  incidentally, 
of  the  time  which  must  elapse  before  the  adhesive  power  to 
bricks  of  the  several  mortars  tried  exceeds  this  limit  of  resistance. 


HYDRAULIC  CEMETfTS,  AND  MOKTAES. 


273 


532.  In  giving  the  results,  it  will  be  necessary,  in  many  in- 
stances, to  give  a  diagram  of  the  surface  of  fracture.    In  such 

cases,  the  splittinsr  of  the  ioints  whereby  a  por- 

'     ^     ^         ^  .  Diagram  of  results, 

tion  of  the  mortars  remains  upon  each  brick,  is 

represented  by  a  dotted  surface,  the  tearing  out  of  a  part  of  the 
brick  is  shown  by  a  surface  shaded  in  parallel  lines;  and  a 
clean  separation  from  the  bricks  by  a  plain  white  surface. 
When  the  fracture  takes  place  continuously  either  in  brick  or 
mortar,  or  is  a  continuous  separation  of  one  from  the  other,  or 
when  the  end  of  a  brick  breaks  off,  the  fact  is  so  stated,  and  no 
diagram  given.  Each  marginal  sketch.  Table  XXXII.,  repre- 
sents the  area  of  the  entire  joint  between  two  bricks. 

533.  The  bricks  were  left  on  shelves  in  the  open  air,  and 
those  marked  thus,  *,  were  wetted  with  a  sponge  two  or  three 
times  a  week. 

534.  TABLE  XXXII. 

Showing  the  resistance  which  Croton  bricks  cemented  together 
crosswise,  in  pairs,  face  to  face,  offer  to  a  force  of  traction  ap- 
plied at  right  angles  to  the  surfaces  of  contact.  The  "  siftings" 
used  in  some  of  the  mortars  are  the  coarse  particles  of  un- 
ground  cement,  which  would  not  pass  wire  sieve  JNTo.  80. 
Age  of  mortars,  320  days. 


No.  of  mortar.  1 

Kind  of  cement. 

Composition  of  mortar. 
The  measurements  are  by  volume. 

Breaking 
weight 

by  force 
of  trac- 
tion, in 
lbs. 

Kemarks. 

1 

Delafield  &  Baxter.... 

stiff  paste  of  pure  cement  

1,097 

Fig  a. 

2 

H 

U  M 

1,101 

End  of  brick  broke  off. 

8* 

"  a 

l|i 

Fig.  6. 

M  a 

843 

End  of  brick  broke  offi 

18 


274 


PKACTIC.VL  TREATISE  O'N  LIMES, 


No.  of  mortar,  j 

Kiud  of  cement. 

Composition  of  mortar. 
The  measurements  are  by  volume. 

Breaking 
weight 

by  force 
of  trac- 
tion, in 
lbs. 

Eemarks. 

6 

Lawrence  Cement  Co. . 

Stiff  paste  of  pure  cement  

898 

Fig.  c. 

6 

7* 

8* 
9 

M 

W 
ti 

>i  u 

u  u 

1,258 

1,242 

1,284 
1,398 

End  of  brick  broke  off. 

J  Continuous  fracture  in  the 

1  brick. 

End  of  brick  broke  off. 

10 

Kingston  &  Eosendale. 

((  u 

1,227 

Fig.  d. 

11 

u 

u  u 

969 

End  of  brick  broke  off. 

12* 

u 

836 

Fig.  e. 

18* 
14 

u 

M  M 

U                        U  '"'^ 

1,284 
1,055 

End  of  brick  broke  off. 

Sancoclc,  Maryland... 

M  U 

648 

Fig./ 

16 

u 

W  »• 

777 

End  of  brick  broke  off. 

17 

M 

M  » 

1,023 

Fig.  g. 

18 

tt 

U 

617 

Fig.  h. 

19 

Newark  &  Eosendale.. 

W  H 

1,213 

End  of  brick  broke  off. 

20* 

James  Kiver  

l(  U 

859 

Fig.  i. 

>  «^ 

^  i 

21 

Delafield  &  Baxter .... 

Cement  in  powder  8,  siftings  1 . 

1,278 

Brick  broke  off. 

22 

Fig.^-. 

u 

Cement  in  powder  4,  siftings  1 . 

979 

Fig.  b. 

HYDRAULIC  CEMENTS    AND  MOETARS. 


275 


Kind  of  cement 


Composition  of  mortar. 


The  meaaurements  are  by  volume. 


Breaki'g 
weight 
by  force 
of  trac 
tion,  in 


Kemarks. 


Delafield  &  Baxter. 


Cement  in  powder  4,  siftings  1 
Cement  in  powder  2,  siftings  1 , 

M  U 

Cement  in  powder  1,  Biftings  1 , 


843 

1,182 
1,211 

1,310 

1,246 
1,180 

1,043 


Cement  in  powder  1,  siftings  2. 


Cement  in  powder  4,  sand  1 


812 


570 


1,192 
1,096 


974 


1.055 


Fig.Z. 


End  of  brick  broke  off. 

I  Broke  out  a  continuous 
<     piece  in  the  brick  avcr- 

(    aging  i  to  i  in.  tliick. 


Fig.  m. 


End  of  brick  broke  off. 
Fig.  n, 


Fig.o. 


Fig.  p. 


Fig.  q. 


Fig.  r. 


j  Continuous  sep;irauon 
(     from  the  brick. 

Brick  broke  off. 


Fig.  «. 


Fig.  t. 


Fig.  u. 


276 


PRACTICAL  TREATISE  ON  LIMES, 


Kind  of  cement. 


41 


42 


47 


48* 


M 


661 


DelafieldA  Baxter., 


Composition  of  mortar. 


The  measurementa  are  by  yoIam«. 


Cement  in  powder  4,  sand  1 . 


Cement  in  powder  2,  sand  1. . 


Cement  in  powder  1,  sand  1. . . 


Cement  in  powder  1,  sand  2 


Breaking 
weight 

by  force 
of  trac- 
tion, in 


1,420 


1,023 


1,113 


1,070 


420 


732 


812 


523 


367 


260 


491 


Eemarks. 


Fig.  V. 


Brick  broke  off, 

J  Continuous  splitting 

\     through  the  mortar. 


Fig.  w. 


Fig,  X. 


Fig,  y. 


0 


a 


Continuous  splittuuc 
through  the  m(  rt  xi 


Fig,  z. 


Fig  A. 


Continuous  splitting 
through  the  mo  ar. 


FigB. 


Fig.  C 


(  Continuous  separation 
<     from    brick.  SampL 
(    probably  defective. 


Fig  D. 


Fig.  F. 


HYDEAULIC  CEMEOTS,  AND  MOETAES.  277 


Kind  of  cement 


Composition  of  mortar. 


The  measurementB  are  by  volume. 


Breaking 


by  lore 
of  trac 
tion,  ii 
lbs. 


Remarks. 


S6 


5T* 


68 


63* 


64* 


65 


James  Eiver. 


Cement  in  powder  8,  sand  1. . . , 


(  Nfiwark  Lime  and 
\  Cement  Mfg.  Co. 


Cement  in  powder  4,  sand  1. 


Cement  in  powder  1,  sand  1. 
Cement  in  powder  1,  sand  2. 


Stiff  paste  of  pure  cement. 


Cement  in  powder  1,  sand  1. . . 


67 


68* 


Cement  in  powder  1,  sand  2. . . 


978 


812 


Fig.  F. 


Fig  G. 


Fig.  H. 


740 
392 

1001 
1,492 


Continuous  separation 
from  the  brick. 


Brick  broke  oflF. 


?.  I. 


Fig.  J.  defective. 


1,451 


913 


Fig.  K. 


Fig.  L. 


Fig  M. 


1,036 


Continuous  splitting 
througb  the  mortar. 


Fig.  N. 


Fig.O. 


278 


PEAOTICAL  TREATISE  ON  LIMES, 


71 


Kind  of  cement 


Newark  Lime  and 
Cement  Mfg.  Co. 


Composition  of  mortar. 


The  measurements  are  by  volume. 


Breaking 
weight 

by  force 
of  trac- 
tion, in 


Cement  in  powder  1,  sand  2. . . 


Eemarka. 


Fig.  P. 


Fig.  Q. 


(  Continuous  separation 
1    from  tlie  brick. 


535.  The  positive  deductions  from  tfie  foregoing  table  appear 
to  be  as  follows : 

1st.  That  particles  of  unground  cement  exceeding  -^q  inch  in  diameter  may  be 
allowed  in  cement  paste  without  sand  to  the  extent  of  fifty  per  cent,  of  the 
whole,  without  detriment  to  its  adhesive  or  cohesive  properties,  while  a  cor- 
responding proportion  of  sand  injures  the  strength  of  the  mortars  in  these 
respects  about  forty  per  cent, 

2d.  That  when  these  unground  particles  exist  in  the  cement  paste  to  the  extent  of 
sixty-six  per  cent,  of  the  whole,  the  adhesive  strength  is  diminished  about 
twenty-eight  per  cent.  For  a  corresponding  proportion  of  sand,  the  diminu- 
tion is  sixty-eight  per  cent. 

3d.  The  addition  of  these  siftings  exercises  a  less  injurious  effect  upon  the  cohesive 
than  upon  the  adhesive  property  of  cement.  The  converse  is  true  when  sand, 
instead  of  siftings,  is  used. 

4th.  In  all  the  mixtures  with  siftings,  even  when  the  latter  amounted  to  sixty-six 
per  cent,  of  the  whole,  the  cohesive  strength  of  the  mortars  exceeded  its 
adhesion  to  the  bricks.  The  same  results  appear  to  exist  when  the  siftings 
are  replaced  by  sand,  until  the  volume  of  the  latter  exceeds  twenty  per  cent, 
of  the  whole,  after  which  the  adhesion  exceeds  the  cohesion. 

6th.  At  the  age  of  320  days  (and  perhaps  considerably  within  that  period),  the 
cohesive  strength  of  pure  cement  mortar  exceeds  that  of  Crotoif  front 
bricks.  The  converse  is  true  when  the  mortar  contains  fifty  per  cent,  or 
more  of  sand. 

6th.  "When  cement  is  to  be  used  without  sand,  as  may  be  the  case  when  grouting 
is  resorted  to,  or  when  old  walls  are  to  be  repaired  by  injections  of  thin 
paste,  there  is  no  advantage  in  having  it  ground  to  an  impalpable  powder. 

536.  The  ingenious  device  mentioned  below,  for  laying  stone- 
^  ^  .  masonry  in  cement-mortar  under  water,  was 
Btone  under  water    suggested  to  me  by  Major  B.  S.  Alexander, 


HYDRAULIC  CEMENTS,  AND  MOETARS. 


279 


Corps  of  Engineers,  and  was,  I  believe,  practised  by  that  officer 
in  the  construction  of  the  Minot's  Ledge  Light-House,  Boston 
harbor.  It  consists  in  protecting  the  mortar  from  the  dissolv- 
ing action  of  the  water  during  the  descent  of  the  stone  to  its 
bed,  by  an  envelope  of  muslin  sufficiently  loose  in  texture  to 
allow  the  mortar  to  ooze  through  between  the  fibres,  and  thus 
form  a  bond  with  the  stone  previously  laid.  The  idea  is  an- 
alogous to  that  followed  by  some  Italian  engineers  in  repair- 
ing and  protecting  submarine  masonry  by  concrete,  rammed 
into  position  in  bags  of  loose,  open  texture.  It  may  be  ap- 
plied in  the  following  manner,  viz. :  a  piece  of  muslin  of 
suitable  quality,  and  somewhat  larger  than  the  bed  of  the  stone 
to  be  laid,  is  first  spread  out  on  a  horizontal  surface  and  cov- 
ered with  a  coat  of  mortar  of  the  thickness  desired  in  the  work, 
and  of  an  area  somewhat  exceeding  that  of  the  bed  of  the 
stone.  On  this  mortar  the  stone  is  then  carefully  placed  and 
allowed  to  remain  there  until  the  mortar  begins  to  stiffen  a 
little,  the  margin  of  the  cloth  exterior  to  the  stone  having  been 
folded  up  against  the  sides  of  the  latter,  and  secured  there  by 
cords  leading  over  the  top.  The  stone  is  then  lowered  to  its 
position  on  the  wall,  rammed  into  place,  and  not  again  dis- 
turbed. 

537.  Some  trials  made  with  a  view  to  test  the  efficacy  of 
this  method  of  construction,  although  giving 

discrepant  results,  show,  that  if  applied  with  Jbt^f^S^.^. 
care,  it  may  be  made  to  subserve  a  good  pur- 
pose. Bricks  were  cemented  together  in  pairs,  as  shown  in 
the  table  last  given.  Some  of  them  had  cement  paste  only 
between  them,  others  had  a  single  layer  of  muslin  next  to  one 
of  the  bricks,  and  others  had  muslin  in  the  centre  of  the 
mortar  joint.  Other  trials  were  made  with  prisms,  2"x2"  in 
cross  section,  with  a  layer  of  muslin  extended  transversely 
across  and  through  the  prism,  midway  between  the  supports 
on  which  the  prisms  were  broken. 

538.  Cement  jpaste  without  sand  was  used  in  all  cases,  and 


280 


PEACTICAL  TREATISE  ON  LIMES, 


the  samples  were  ninetj-six  days  old  when  broken.  Water  was 

applied  to  them  with  a  sponp-e  two  or  three 
Same  continued.       .  i     i     .  i 

times  a  week,  durmg  the  entire  period.  All 

the   bricks  were   cemented  while  thoroughly  wet.  Table 

XXXIII.  contains  the  results.    The  numbers  15, 16,  IT,  and  18 

were  dipped  in  sea-water  just  before  being  cemented. 


539.  TABLE  XXXIII. 

Showing  the  adhesive  and  cohesive  strength  which  mortars 
of  pure  cement  paste  can  attain,  through  a  layer  of  com- 


o 
?5 


Mode  of  trial. 


to 

a  ua 

oj.a  j 


Eemarks. 


Two  wet  bricks  cemented  together,  without  muslin. 


:  t 
■  I 


with  wet  muslin  in  ' 
the  middle  of  the 
joint. 


with  muslin  soaked  I 
in  crean  of  cement  > 
next  to  one  of  them  ) 


muslin  soaked  in 
cream  of  cement, 
and  bricks  dipped 
in  sea-water. 


572 


279 


884 


939 


908 
572 

82 

94 
106 

978 

709 
1153 
572 
719 

1153 

197 

872 
185 


Fig.  K. 


j  Continuous  separation 
\    from  brick. 


Fig.  S. 


Fig.  T. 


End  of  brick  broke  off. 
J  Continuous  separation 
1    from  brick. 


Separated  along  the  muslin. 


End  of  brick  broke  off. 

Separated  along  the  muslin. 
End  of  brick  broke  off. 
Separated  along  the  muslin. 


Continuous  separation 
from  brick. 


HYDEAULIC  CEMENTS,  AND  MOETAES. 


281 


mon  thin  muslin.    The  mortar  set  under  a  pres- 

.  Same  continued, 

sure  of  thirty-eiglit  pounds  per  square  inch,  or 

about  500  pounds  on  the  pair  of  bricks.     Age  of  mortar, 

ninety-six  days. 

540.  OBSERVATIONS  ON  THE  FOREGOING  TABLE. 

1 .  The  average  resistance,  where  there  is  a  continuous  separation  from  the  muslin, 

is  507  pounds. 

2.  The  average  resistance,  where  there  is  a  continuous  separation  from  the  brick, 

and  no  mushn  was  used,  is  425  pounds. 

3.  The  average  resistance,  where  there  is  a  continuous  separation  from  the  brick, 

and  mushn  was  used,  is  446  pounds. 

4.  The  average  resistance  of  all  the  cases  where  muslin  was  used,  is  568  pounds. 
6.  The  average  resistance  of  all  the  cases  where  muslin  was  not  used,  is  692  pounds. 
6.  The  case  of  muslin  soaked  in  cream  of  cement  next  to  one  of  tlie  bricks,  gave 

the  best  average  result,  viz.:  826  pounds;  the  next  best  being  when  the 
bricks  are  put  together  without  muslin,  which  gave  an  average  of  632 
pounds. 

1.  The  three  greatest  resistances  in  the  above  table  were  obtained  when  muslin 
was  used.  In  two  of  these  (Nos.  10  and  12),  the  end  of  one  brick  broke 
off;  in  the  third,  (No.  15,)  the  separation  took  place  continuously  along  the 
muslin. 

8.  The  worst  results,  when  musHn  was  used,  were  obtained  when  the  latter  was 
placed  in  the  centre  of  joint,  and  not  in  contact  with  either  brick,  the  differ- 
ence being  very  considerable,  as  an  inspection  of  the  table  will  show. 
The  muslin  used  in  these  trials  was  much  thicker  than  would  be  necessary  in 

practice. 

541.  TABLE  XXXIY. 


other  trials 
with  muslin. 


Showing  the  strength  of  rectangidar  jprisim  x  2" 
in  cross-section,  some  of  them  having  a  hiyer  of 
muslin  transversely  across  the  prisms,  midway  between  the  sup- 
ports, and  some  having  none.  The  prisms  were  ninety-six  days 
old,  of  pure  cement  paste,  the  supports  four  inches  apart.  The 
pressure  was  applied  in  the  middle. 


Nature  of  test 


Piece  of  muslin  transversely  across  the  prism 
No  muslin  was  used  


C  CO 


113 
103 
353 
337 
322 
304 


Bemarks. 


Broke  along  the  muslin. 


282 


PRACTICAL  TREATISE  OJ^  LIMES, 


542.  OBSERVATIONS  ON  THE  FOREGOING  TABLE. 

1.  The  average  breaking  weight  of  the  prisms  containing  muslin,  is  107  pounds; 

and  of  those  containing  no  mushn,  329  pounds. 

2.  The  8th  observation  of  Table  XXXIII.  is  corroborated,  viz. :  that  the  most  dis- 

advantageous place  for  the  muslin  is  in  the  body  of  the  mortar. 

3.  With  thin  raushu  of  loose  texture,  both  the  adhesion  and  cohesion  through  the 

muslin  would  undoubtedly  b§  much  greater  than  the  foregoing  Tables 
(XXXIII.  and  XXXIV.)  indicate. 


The  effect  of  the 
sand  on  the  ad- 
hesive properties 
of  mortars. 


543.  TABLE  XXXY. 

Showing  the  adhesion  to  Croton  front  hrielcs 
and  fine  cut  granite^  of  mortars  containing  dif- 
ferent proportions  of  sand.  The  mortar  was  of 
the  consistency  ordinarily  used  for  brick  masonry, 
and  the  bricks  were  nsed  wet,  and  were  pressed  well  too:ether 
by  hand.  They  were  wetted  with  fresh  water  every  alternate 
day  for  29  days,  the  age  of  the  mortar  when  tested.  Each  re- 
sult is  the  average  of  five  trials.  The  right-hand  column  shows 
the  ratio  of  the  adhesive  strength  of  the  several  mortars,  assum- 
ing that  of  pure  cement  to  be  1. 


Composition  of  the  mortar. 


Materials 
cemented. 


IS 

9 

«  5;  o  rt 

O  o 

^  1 

.2  S 

M 

421 

30.f 

1 

215 

15.7 

-No 

169 

12.3 

94 

6.h 

71 

5.2 

59 

4.3 

45 

3.3 

.1 1. 

1  00 

4401 
332| 

27.5 
20.b' 

1 

201 

12.C 

-1%%- 

146| 

9.2 

127 

7.P 

Pure  cement  paste  

1  vol.  cement  powder,  1  vol.  sand 
1    "       "  "      2  " 

1^    <(       ((  ((      2  « 

((  U  ((         ^  u 

I    "  "      5  " 


Pure  cement  paste  

1  vol.  cement  powder,  1  vol.  sand 

1  "  "  2 

II       (<  ((      2  u 


Croton  bricks. 


Fine  cut  granite, 


544.  The  adhesion  of  mortars  to  stone  or  bricks  varies  con- 
siderably among  the  different  kinds  of  these  materials,  and  par- 
ticularly with  their  porosity. 

With  the  same  material,  it  varies  with  the  consistency  of  the 
mortar,  and  the  quantity  of  sand  which  it  contains. 


HYDEAULIC  CEMENTS,  AND  MOETAKS.  283 


645.  TABLE  XXXYI. 


Showing  the  adhesion  to  very  fine  cut  granite  of  pure  ce- 
ment made  by  the  I^ewark  &  Kosendale  Co.,  mixed  with 
different  proportions  of  water.  The  blocks  measured  4"  x  8" 
on  the  face,  and  were  cemented  together  in  pairs,  face  to  face, 
at  right  angles  to  each  other,  and  kept  in  fresh  water.  The 
stones  were  pressed  together  by  hand,  as  in  laying  bricks,  and 
were  pulled  apart  at  the  expiration  of  96  days  by  the  device, 
shown  in  Fig.  5. 


o  a 


Composition  of  the  mortar. 


1  vol.  loose,  dry  cement,  and  \  vol.  water.   Consistency  of  cream  

((                                                    ((  u 

l(                            C(                            1.1.                      (I  II  u 

1  vol.  loose,  dry  cement,  and  -iij.  vol.  water.  Consistency  of  very  thick  creain 

U                          (I                                                (I  u                               u  » 

II                              ((                               (I                         »  »                                     K  (I 

»                                                               C(                         !.<.  U                                     K  » 

1  vol.  loose,  dry  cement,  and  -^^^  vol.  water.  Consistency  of  ordinary  mortar. 


2.4 

O)  o 


|?U0ilbs. 

314  J 
6111 

.584  i  3^1^  u 

591  r  '4 

599  J 
454] 


490 
449 
472 


546.  For  the  sake  of  economy,  it  is  customary  to  add 
lime  to  cement  mortars,  and  this  may  be 
done,  to  a  considerable  extent,  when  in  positions  sake^oT  economy 
where  hydraulic  activity  and  strength  are  not  re- 
quired in  an  eminent  degree.  The  following  table  contains  the 
results  of  trials  with  cement  paste  and  mixtures  of  cement  and 
lime  paste,  without  sand.  The  cement  was  the  dark  Kosendale 
of  excellent  quality. 

54:7.  TABLE  XXXYIl. 

Showing  the  ultimate  strength  of  rectangular  parallelopijyeds 
X  2"  X  8'')  of  cement  paste,  and  mixtures  of  cement  and  lime 
paste  without  sand,  formed  in  vertical  moulds,  under  a  pres- 
sure of  32  lbs,  per  superficial  inch,  and  broken  when  95  days 


284 


PRACTICAL  TREATISE  OK  LIMES, 


old,  on  supports  4  inches  apart,  by  a  force  applied  at  the  middle. 
The  mortars  were  kept  in  sea-water  from  the  time  they  were 
one  day  old. 


Composition  of  the  cement 


Pure  cement  paste.   (Average  of  two  trials.) 

1,1  il  It  (I 

Cement  paste,  1  vol.   Lime  paste,  i  vol  


ivol. 


1vol. 


ivol. 


ivol. 


1  vol. 


Penetration  of  the 
point  in  inches. 


1  impact.  2  impacts.  ^  S  tS 


.114 
.112 
.117 
.lOT 
.155 
.160 
.147 

.155 
.155 
.150 
.159 
.121 
.200 
.180 

.187 

.iso 

.207 
.210 
.180 
.200 
.180 
.180 
.200 
.220 
.230 
.270 


3  S 


.195 
.163 
.192 
.187 
.250 
.250 
.243 

.250 
.265 
.200 
.195 
.200 
.300 
.220 

.395 
.295 
.325 
.330 
.300 
.320 
.293 
.290 
.300 
.340 
.260 
.380 


994 

957 

,025 

,034 

,0!)0 

996 

992 

931 

S63 

847 

1S5 

769 

597 

570 

513  I 

582  J 

597^ 

574  1 

558  f 

550  J 

3f.5~l 

363  ! 

355 

375 

339 

316 

286 

280 


l,002i  lbs. 


9793 


816 


565* 


5693. 


364t 


305^ 


548.  Othe?'  mortars  of  light  colored  E-osendale  cements  and 
lime,  mixed,  formed  into  blocks  of  the  same  size,  preserved  and 
broken  in  precisely  the  same  manner  as  the  foregoing,  gave  the 
following  results  when  95  days  old.  The  average  of  four  trials 
is  given  in  each  case. 

TABLE  XXXVIII. 


No.  of 

the 
mortar. 

Composition  of  the  mortar. 

Breakino; 
weight,  in  lbs. 

1 

Cement  pas 

738 

2 

u 

1    "       "     i  "   

3 

u 

732 

4 

'it 

]^            u                      "1  " 

608 

Effect  of  lime  on 
the  strength  of 
cement  mortar. 


549.  Observations  on  Tables  XXX  YII,  and 
XXX F//Z— 1st.  We  infer  from  the  last  ta- 
bles (XXXVTI.  and  XXXYIIL),  that  the  dark 


HYDEAULIC  CEMENTS,  AND  MORTARS. 


285 


colored  Eosendale  cements  are  less  able  to  sustain  a  large  dose 
of  lime  than  those  that  are  light  colored,  and  that  the  latter 
suffer  no  serious  deterioration  of  strength  until  the  amount  of 
lime  paste  exceeds  the  amount  of  cement  paste. 

It  does  not  necessarily  follow  that  the  ingredients  which 
confer  color  on  the  cement  are  the  cause,  either  immediate  or 
remote,  of  this  difference.  The  light  colored  Rosendale  ce- 
ments are  confined  to  one  locality,  that  of  High  Falls,  and  it 
may  be  that  local  causes,  operated  at  the  period  of,  or  subse- 
quent to  their  deposition,  which  so  modified  or  changed  the 
molecular  or  chemical  condition  of  some  of  the  ingredients,  as 
to  cause  this  variation,  and  at  the  same  time  be  beyond  the 
reach  of  ordinary  analytical  research. 

550.  2d.  In  Tables  XXXYII.  and  XXXYIII.,  no  record  is 
made  of  the  effects  which  the  addition  of  lime  has  on  the  hy- 
draulic activity  of  the  cement.  In  regard  to  Effect  of  lime  on 
this  point,  however,  numerous  trials  show  that  Jf^^ty^ol-'cem^^ 
a  gang  composed  of  equal  proportions  of  the  mortars, 
pastes  of  Rosendale  cement  and  lime  is  sufficiently  quick  set- 
ting for  all  purposes,  except  when  immediate  submersion  is 
required ;  and  possesses,  besides,  the  positive  advantage  over 
pure  cement  of  coming  to  the  hands  of  the  masons  in  a  better 
working  condition,  and  is  not  liable  to  have  its  incipient  set 
constantly  disturbed  on  the  mortar  board,  and  its  ultimate 
strength  thereby  impaired  by  remixing.  There  is  a  remarka- 
ble difference  in  the  capacity  of  cements  to  withstand  this 
degrading  treatment.  The  extent  to  which  they  are  affected 
by  it  seems  to  vary  directly  with  their  hydraulic  activity 
Thus,  the  Rosendale  cements,  which  require  25  to  30  minutes 
to  set  at  65°  F.,  will  bear  reworking  much  better  than  those 
James  and  Potomac  River  cements,  which  harden  in  five  or  six 
minutes.  We  would  expect  that  the  extent  of  the  disturbance 
of  the  crystallization  would  be  in  direct  proportion  to  the  hy 
draulic  activity. 

651.  The  me  of  alkaline  silicates  {soluble  glass)  as  a  means 


286 


PEACTICAL  TEEATISE  Olf  LIMES, 


of  conferring  hydraulic  energy  upon  fat  lime  has  been  reverted 
to  in  foregoing  portions  of  this  work.  Experiments  uniformly 
indicate  that  its  efficiency  for  such  purposes,  has  been  overrated. 
It  may,  and  probably  can  be  advantageously  applied  to  the 
reclamation  of  the  intermediate  limes,  (those  in  which  the  hy- 
draulic energy  is  exerted  powerfully  and  rapidly  when  first 
mixed,  but  which  soon  yield  and  fall  down  under  the  action  of 
the  sluggish  free  lime  present) ;  but  for  fat  limes,  they  appear 
so  unsuitable,  that  even  the  statements  of  M.  Kuhlmann  him- 
self are  insufficient  to  authorize  their  use.  When  added  to  the 
intermediate  limes,  they  appear  to  exert  their  influence  by  giv- 
ing up  their  silica  to  the  free  lime  present,  thus  neutralizing  or 
perhaps  only  retarding  its  action,  until  the  hydraulic  principle 
has  time  to  exert  its  indurating  power. 

552.  Presuming,  under  ordinary  circumstances,  that  the  ad- 
dition of  soluble  glass  to  a  paste  of  fat  lime  not  only  conferred 
hydraulicity,  but  augmented  the  strength  of  the 

Effect  of  soluble        '     ,  j.  •  i  i    -  i  •      .  i 

glass  on  the         mortars,  some  trials  were  undertaken  with  the 

strength  of  mor-  double  silicate  of  potash  and  soda,  in  order  to 
test  its  relative  value  when  thus  employed,  as 
compared  with  hydraulic  cement  itself.  The  specific  gravity 
of  the  soluble  glass  used  was  39°  Beaume,  at  O^''  F.  Prisms 
of  the  usual  size  were  made  and  kept  in  the  air  ninety-five  days, 
when  they  were  broken  in  the  usual  manner,  on  supports  four 
inches  apart.  In  the  following  table,  the  breaking  weights  are 
given  in  the  right  hand  column.  The  first  and  second  samples 
were  formed  under  a  pressure  of  32  pounds  per  square  inch, 
the  others  without  pressure. 

The  adhesion  to  bricks  cemented  together  transversely  is  as 
follows : 


rormona.of|«««^;J[  9,,}  lbs. 

( limepaste 
•<  sand 

(  soluble  glass  .125 


( limepaste  1.0  ) 

For  mortar  of  i  sand  3.0    1 51 1  lbs. 


HYDBAULIC  CEMENTS,  AND  MORTARS. 
TABLE  XXXIX. 


287 


o 

is 


3 
4 
5 
6 
1 
8 
9 
10 
11 
12 


Composition  of  the  mortar,  in  volumes. 


Lime  paste,  1.0,  sand,  2.0,  soluble  glass,  .11.  . 

1.0,  "  2.0,       "       "  .11.. 

"          1.0,  "  2.0  

"          1.0,  "  2.0  

"          1.0,  "  3.0  

"          1.0,  "  3.0,  soluble  glass,  .08. . 

"          1.0,  "  3.0,       "       "  .10.. 

1.0,  "  3.0,               "  .125. 

"          1.0,  "  3.0,  cement  paste  .50. . 

"          1.0,  "  3.0,       "       "  .33.. 

"          1.0,  "  3.0,       "       "  .25.. 

"           1.0,  "  3.0,        "       "  .166. 


— =2 .9 


40 
54 

in 

67f 

65 

24i 

23 

18 
1821 
166f 

92 

94| 


It  injures  the 
strength  and  ad- 
hesive properties 
of  mortars. 


553.  From  the  foregoing  results,  which  are  the  averages  of  many 
trials,  it  may  be  inferred  that  the  double  alkaline  silicate,  while 
it  renders  common  mortar  hydraulic,  injures  its 
strength  and  its  adhesive  properties,  and  is 
greatly  inferior  to  cement  as  a  hydraulic  agent, 
in  both  efficiency  and  economy,  irrespective  of 
the  degree  of  energy  required.  At  the  same  time,  it  is  con- 
ceded that  in  many  cases,  particularly  for  hardening  soft  and 
porous  stones  and  concrete  walls  or  stucco  work,  after  these 
are  well  dried,  it  is  of  value  when  judiciously  applied.  Its  use 
has,  however,  been  attended  with  many  failures,  even  in  France, 
where  the  subject  has  received  much  attention,  and  we  are  yet 
without  an  easy  and  entirely  practicable  method  of  manipula- 
tion, that  can  safely  be  intrusted  to  the  hands  of  ordinary  me- 
chanics.   Silicate  of  soda  should  be  employed  rarely  if  at  all. 

554.  The  experiments  undertaken  to  ascertain  the  law  of 
progressive  increase  in  the  strene::th  and  hard-  , 

^    ^  °  Increase  of 

ness  of  mortars  of  American  cements  do  not  ex-    strength  and  hard- 
tend  over  a  very  large  period  of  time.    The  re- 
sults obtained,  however,  afford  the  means  of  a  very  fair  com- 
parison between  the  strength  of  these  mortars  and  some  placed 
on  trial  at  Toulon,  with  a  view  to  determine  the  combinations 


288 


PRACTICAL  TREATISE  OJST  LIMES, 


to  be  used  in  the  construction  of  the  dock  in  that  harbor^ 
under  the  superintendence  of  M.  Noel,  Engineer-in- chief  of 
Roads  and  Bridges.  The  trials  at  Toulon  were  made  during 
the  years  1840  to  1844:,  upon  rectangular  prisms  1.57  inches 
wide  by  .984  inches  deep ;  they  were  broken  on  supports  2.36 
inches  apart,  by  a  pressure  at  the  middle. 

A  comparison  of  the  results  obtained  in  the  two  cases  has 
been  made  by  using  the  formulas  : 

(1 .)  W^l  E  ^  -  - 1      (2.)  W'=  f  R  ^' 

In  the  general  formula  (1)  W  represents  the  weight  which 
the  prism  bears  at  the  moment  of  rupture ;  J,  the  breadth,  and 
d,  the  depth  of  the  prism  ;  Z,  the  distance  between  the  supports, 
and  a,  the  weight  of  that  portion  of  the  prism  represented  by  1. 

The  value  of  R,  the  co-efficient  of  rupture,  having  been  ob- 
tained from  the  above  equation  from  M.  I^oel's  prisms,  by 
substituting  for  W,  h,  d,  Z,  and  their  known  values  as  reported 
we  readily  obtained  the  value  W  for  M.  Noel's  mortar  wheD 
the  prisms  are  supposed  to  be  two  inches  square  in  cross  sec- 
tion, and  broken  on  supports  four  inches  apart,  like  the  Amer- 
ican mortars,  by  substituting  in  equation  (2)  the  deduced  value 
of  R,  and  the  value  of  h',  d',  l\  and  a\  corresponding  to  the 
American  prisms. 

555.  The  results  of  the  computations  above  mentioned,  which 
are  the  resistances  to  rupture  of  rectangular  prisms  2"x 
2"  in  cross  section,  resting  on  supports  four  inches  apart, 
are  given  in  Fig.  56,  by  curves  constructed  with  abscissas, 
which  represent  the  resistances  or  breaking  weights,  laid  down, 
to  a  scale  of  yV  of  an  inch  to  20  pounds,  and  with  ordinates, 
which  represent  the  age  of  the  mortars  to  a  scale  of  of  an  inch 
to  twenty-five  days.  The  mortars  were  kept  in  salt  water  imtil 
broken. 

The  proportions  of  cement,  lime,  and  sand  are  given  by  vol- 
ume in  all  cases. 


HYDKAULIC  CEMENTS,  AND  MOETARS.  289 


Jos. 

1250 

1 
1 

fl?o 

MOO 

J050 

j  

1820 

j 

[ 

m . 

350  - 

-j  

BOO 



// 



— 



750  " 

/  \ 
!  2 

700 

^ — ; 

esp  - 

/ 

i 

fiOP 

f\ 

1 — 

550  - 

/ 

/ 

— ^.  / 

5^  

■-1  -g- 

-  / 
1 

/ 

^1 

-T  

/  ^ 

— • 

- — 

^_  s- 

 . 

400 

n 

-]  

\U 

} 

/  y 



 ^ 

300 

4 

r 

/  / 

/ 

-j  

1 

/ 

 ft" 





150  I 

i 

H 

T~ 

m] 

1 

fo  j 

ff«cri.20    60  n 

0            200            300             ^00            600             600           700             fiOO     ^  000 

19 


Fig.  55. 


290 


PRACTICAL  TREATISE  ON  LIMES, 


No.  1.  Mortar  composed  of  two  parts  Roman  pozzuolana  and  1.50  parts  Theil 
hydraulic  lime. 

No.  2.  Mortar  composed  of  two  parts  Roman  pozzuolana  and  1  part  ordinary 
lime. 

No.  3.  Mortar  composed  of  two  parts  Roman  pozzuolana  and  1  part  Theil  hy-  . 
draulic  lime. 

No.  4.  Mortar  composed  of  two  parts  sea-sand  and  1  part  Theil  hydraulic  lime. 

No.  5.  Mortar  composed  of  one  part  Roman  pozzuolana,  one  part  Theil  hydraulic 
lime,  and  one  part  sea- sand. 

No.  6.  Mortar  composed  of  one  part  Roman  pozzuolana,  one  part  ordinary  lime, 
and  one  part  sea-sand. 

No.  1.  Mortar  composed  of  one  part  Rosendale  and  Kingston  cement  and  one 
part  sand. 

No.  8.  Mortar  composed  of  one  part  Ogden's  Rosendale  cement,  and  one  part 
sand. 

No.  9.  Mortar  composed  of  one  part  Hudson  River  cement,  and  one  part  sand. 
No.  10.  Mortar  composed  of  one  part  Lawrence ville  Cement  Manufacturing  Co., 
and  one  part  sand. 

556.  Of  the  four  American  cements  represented  in  Fig.  56, 
Nos.  7,  9,  and  10  are  what  are  known  as  "  dark"  colored,  and  take 
the  initial  set,  so  as  to  support  the  ,V  inch  wire,  loaded  to  J  of 
a  pound,  in  from  twenty-five  to  thirty  minutes,  at  a  tempera- 
ture of  65°  F. 

^^J'o.  8  is  a  "  light"  cement,  manufactured  from  Layer  "No.  16 
at  High  Falls,  (see  paragraph  55).  It  sets  very  rapidly,  (in  from 
five  to  eight  minutes,)  when  first  mixed,  provided  the  paste  is 
not  mixed  too  long,  and  is  left  entirely  undisturbed  ;  but  if  the 
manipulating  process  continues  beyond  the  time  when  the  in- 
duration properly  begins,  the  continual  breaking  up  of  the  in- 
cipient set  destroys  the  energy  very  much.  It  is  far  more 
sensitive  in  this  particular  than  the  slower  acting  cements,  7, 
9,  and  10.  It  may  be  further  remarked  that  of  the  three 
American  cements  whose  trial  extended  through  the  period  of 
one  year,  the  two  slower  setting  "  dark"  colored  varieties  are 
inferior  in  strength  to  the  other  which  is  "  light"  colored  and 
quick,  until  all  attained  the  age  of  about  three  hundred  days, 
when  this  condition  of  things  is  reversed.  From  this  point 
onwards,  the  former  increase  in  strength  very  rapidly,  and  the 
latter  quite  moderately.    At  four  hundred  days,  the  "light"  ce- 


HYDRAULIC  CEMENTS,  AND  MORTARS.  291 


ment  is  no  stronger  than  a  mortar  of  1^  parts  Theil  hydraulic 
lime  and  2  parts  of  Koman  pozzuolana,  (curve  1). 

557.  TABLE  XL. 

Showing  the  strength  of  mortars  of  various  cements  made  into 
prisms  2"  X  2"  X  8"  in  vertical  moulds,  un-    ^       ^  ^ 

^  .  Strength  of  mor- 

der  a  pressure  of  32  pounds  per  square  inch,    tars  of  sundry 
and  broken  on  supports  four  inches  apart,  by  a 
pressure  midway  between  the  supports.    The  prisms  were  kept 
in  sea-water  after  the  first  24  hours,  and  were  320  days  old 
when  broken.    The  breaking  weights  given  are  averaged  from 
many  trials.    The  cement  was  measured  in  powder. 


Breaking  weights  of  mor 
tars  composed  of 


Kind  of  cement  used. 


Pure  ce- 
ment. 


Cement, 
vol.  1, 
Sand, 
vol.  1. 


Cement, 
vol.  1, 
Sand, 
vol.  2. 


English  Portland  (artificial)  

Cumberland,  Md  

Newark  and  Rosendale  

Delafield  and  Baxter  (Rosendale)  

"Hoffman"  Rosendale  

"Lawrence"  Rosendale  

Round  Top,  Md  

TJtica,  111  

Shepherdstown,  Va  

Akron,  N.  Y  

Kingston  and  Rosendale  

Sandusky,  Ohio  

James  River,  Va  

*  Roman  cement,  Scotland  

The  following  were  broken  when  one  year  old: 

Lawrenceville  Manuf.  Co.  (Rosendale)  

Sandusky,  Ohio  

Kensington,  Ct  

Lawrence  Cem't  Co.  (Rosendale)  "Hoffman"  Brand. 
Round  Top,  Md  


lbs. 
1,536 
954 
841 
836 
849 

m 

732 
V47 
764 
720 
554 

553 


802 
954 
875 


lbs. 
1.260 
920 
560 
692 
607 

600 
756 
618 
651 
556 
464 
623 


910 

709 
911 

840 


lbs. 
950 
558 
500 
532 


562 
450 
603 
500 

638 
380 


506 


*  This  cement  appeared  to  be  inferior  in  hydraulic  energy  to  Roman  cement 
generally,  and  had  probably  been  injured  by  age  and  exposure. 

558.  From  General  Treussart''s  experiments  with  mortars  of 
fat  lime  and  trass,  or  pozzuolana,  it  may  be  in-    Q^n.  Treussart's 
ferred  that  these  two  substances  possess  very  experiments. 


292 


PRACTICAL  TREATISE  01^  LIMES, 


nearly  equal  merit,  as  agents  for  conferring  strength  and  hy- 
draulic energy  on  common  mortar.  He  says  pozzuolana  gave 
rather  the  better  results  with  the  same  kind  of  lime ;  although 
"  in  general  there  was  little  difierence  between  the  trass  and 
the  pozzuolana  used." 

The  results  given  in  the  following  table  were  obtained  by  that 
engineer,  and  are  introduced  liere  as  affording  a  just  medium 
of  comparison  between  such  mortars,  and  those  of  the  same  age 
(one  year)  recorded  in  the  table  last  given.    (Table  XL.) 

559.  TABLE  XLI. 

Breaking  weights  of  jpozzuolana  and  trass  mortars^  one  year 
old,  formed  into  prisms  2"  X  2"  X  6",  and  resting  on  supports 
four  inches  apart.  The  lime  was  slaked  to  powder  and  meas- 
ured in  that  condition.    The  prisms  had  been  kept  in  water. 


'SI 


Coinpoaition  of  the  mortar. 


5  S-^ 


Strasburg  lime,  1  vol.,  sand,  1  vol.,  trass,  1  vol  

Strasburg  lime,  1  vol  trass,  2  vol  

Strasburg  limo,  1  vol.,  sand,  1  vol.,  pozzuolana,  1  vol. 

Straeburg  lime,  1  vol  por^uolana,  2  vol. 

Vasselone  lime,  1  vol.,  sand,  1  vol.,  trass,  1  vol  

Yaasolone  lime,  1  vol  tra^s,  3  vol  

Brunstat  limo,  1  vol.,  sand,  1  vol.,  trass,  1  vol...... 

BVunstat  limo,  1  vol  trass,  2  vol  

White  mai'ble  lime,  1  vol.,  sand,  1  vol.,  trass,  1  vol  

White  marble  lime,  1  vol  trass,  2  vol  

White  marble  lime,  1  vol.,  sand,  1  vol.,  pozzuolana,  1  vol. 

White  marble  lime,  1  vol  pozzuolana,  2  vol. 

Strasburg  lime,  1  vol  pozzuolana,  2  vol. 

Strasburg  lime  (paste),  1  vol  pozzuolana,  2^  vol 

Strasburg  lime  (paste),  1  vol  trass,  2  vol  


4 
4 

5 
4 
5 
4 
5 
4 
4 
3 
4 
5 

to  16 


lbs. 
4L1 
330 
499 
444 
449 
385 
510 
535 
308 
407 
396 
367 
495 
550 
231  to  580 


560.  Experiments  seem  to  prove  that  fat  liine  shiked  to 
Lime  with  trass  powder  will  give  better  mortars  with  trass  and 
mortars.  sand,  or  with  trass  alone,  if  left  exposed  to  the 

air  for  a  month  or  more  after  slaking,  than  if  made  into  mortar 
when  perfectly  fresh ;  and  also  that  a  mortar  composed  of  one 
volume  of  lime  powder  and  two  volumes  of  trass,  is  injured  if 


HTBEAULIC  CEMENTS,  AND  MOETAES. 


298 


a  portion  of  the  trass  be  replaced  by  sand.  General  Treussart 
also  found  that  air  slaked  lime  did  not  give  as  good  results  as 
lime  slaked  to  powder  with  water. 


CHAPTER  IX. 

561.  White  alkaline  effloresences  upon  the  surface  of  brick 

walls  laid  up  in  mortar,  of  which  natural  hy- 

T    T  .     ,     T      .      >  ,       Effloresencos  on 

draulic  hme  or  cement  is  the  basis,  irequently    brick  walls  laid  in 

produce  a  most  unsightly  appearance,  and  offer  mortor. 

a  grave  objection  to  the  use  of  cement  for  masonry  exposed  to 

view,  or  where  it  is  desired  to  preserve  any  agreeable  shade  or 

tint,  or  retain  the  natural  color  of  the  brick  employed. 

562.  On  stone,  these  effloresences  never  at- 
tain a  formidable  aspect,  and  with  the  denser    ^^^f  formidable 

^      '  on  stone  walls, 

varieties  are  almost  imperceptible,  being  confin- 
ed exclusively  to  the  pointing  of  the  joints;  but  on  brick  work, 
they  not  unfrequently  spread  themselves  over  the  entire  surface 
of  the  wall. 

563.  A  more  serious  objection  than  any  due 

to  appearance  simply,  is  furnished  by  the  fact  J^nJation™ 
that  the  crystallization  of  these  salts  within  the 
pores  of  the  bricks,  into  which  they  have  been  absorbed  from 
the  mortar,  is  certain  to  cause  disintegration.  Even  stone, 
particularly  the  most  porous  varieties,  is  not  exempt  from  the 
effects  of  this  destructive  agent,  which  acts,  especially  the  soda 
salts,  in  many  respects  like  frost. 

564.  The  exudation  of  those  alkaline  solu- 
tions, which,  in  crystallizing,  produce  deleterious  Ttmosphere. 
salts,  appears  to  be  favored  by  a  humid  state  of 

the  atmosphere,  and  is,  therefore,  more  prominently  developed 
on  the  sea-shore  than  in  localities  more  inland. 

565.  At  Newport,  R.  /.,  pints  of  it  may  at  From  Fort  Adama 
any  time  be  collected  from  the  walls  of  Fort 

Adams.    Being  almost  entirely  soluble  in  water,  it  is  removed 


294 


PEACTICAL  TKEATISE  ON  LIMES, 


by  rain  from  all  localities  exposed  to  the  direct  action  of  this 
element,  to  be  reabsorbed,  in  a  great  measure,  before  the  aque- 
ous solution  has  time  to  run  off. 

566.  A  portion  of  this  Fort  Adams'  efflorescence  takes  the 

Analysis  of  Fort  ^^^^^  ^^^^  ^^^^^  needles,  frequently  pro- 
Adtims'  efflores-      jecting  more  than  one  inch  from  the  face  of  the 

OGUCG. 

wall.  Other  portions  present  the  appearance  of 
fine  snow.  When  collected  in  a  mass,  it  closely  resembles 
Epsom  salts  in  appearance,  and  is  not  unlike  it  in  taste.  Its 
composition,  as  determined  by  analysis,  is  reported  by  Profes- 
sor Boynton,  of  the  University  of  Mississippi  to  be  as  follows : 

Carbonic  acid   19.90 

"Water  expelled  at  a  low  red  heat   52.30 

Lime  04 

Soda   2'7.96 

Sulphuric  acid  10 

lesia  ,  06  • 


100.36 


567.  Another  sample  of  efflorescence  from  the  ruins  of  an 

embrasure  tara^et  erected  at  West  Point  in  the 

w^K.  -.  T      .  ,     .       From  West  Point 

year  18o4,  subjected  to  qualitative  analysis, 

gave  carbonate  of  potash  as  the  principal  ingredient.  Its  ap- 
pearance upon  the  surface  of  the  bricks,  resembled  that  of  a 
thin,  rough  coating  of  white  sugar.  It  was  readily  removed 
as  a  powder  by  scraping. 

568.  M.  Kuhlmann^  of  Lille ^  France,  who  gave  his  attention 

to  this  subject  many  years  ago,  and  who  has 
fxpfriei^e^'''''^      from  time  to  time  published  his  investigations, 

without  proposing  any  efficient  remedy  for  the 
evils  complained  of,  notices  some  efflorescences  of  a  much  more 
complicated  composition  than  those  from  Fort  Adams.  Pro- 
fessor Kuhlmann  found,  that  although  efflorescences  of  nitrate 
of  potash  (saltpetre),  or  ammonia,  were  of  no  rare  occurrence, 
those  of  carbonate  and  sulphate  of  soda  were  much  more  com- 
mon, and  that  many  stone  and  brick  walls,  laid  up  in  hydraulic 


HYDEAULIO  CEMENTS,  AND  MORTARS.  295 


mortar  within  periods  quite  recent,  were  covered  with  exuda- 
tions of  caustic  and  carbonated  potash,  containing  chlorides  of 
potassium  and  of  sodium. 

569.  One  source  of  these  salts  of  soda  and  potash  is,  beyond 
doubt,  the  hydraulic  lime  or  cement  used  in  the 

mortar;  derived  partly  from  the  stone  itself  and potlh!"^ 
and  partly  from  the  ashes  of  the  fuel  used  in 
calcination,  when  the  burning  takes  place  in  ordinary  draw 
kilns.  About  35  lbs.  of  anthracite  coal  are  required  to  calcine 
1  bbl.  (300  lbs.)  of  cement,  and  no  precaution  whatever  is  taken 
to  separate  the  coal  ashes.  From  the  same  cause,  the  cement 
also  becomes  adulterated  with  fine  particles  of  unconsumed 
coal,  amounting  sometimes  to  three  or  four  per  cent,  of  the 
whole.  When  the  cement  is  coarsely  ground,  these  particles 
are  plainly  visible,  but  in  the  condition  of  impalpable  powder, 
they  are  lost  to  the  naked  eye. 

570.  Proximity  to  the  sea,  where  the  atmosphere  is  a  con- 
stant source,  will  account  for  the  preponderance    proximity  to  the 
of  carbonate  of  soda  in  the  walls  of  Fort  Adams,    sea  favors  efflo- 
as  well  as  for  the  exceedingly  large  volume  of 
efflorescence.    It  seems  improbable  that  the  mortar  could  be 
the  origin  of  so  much  alkali. 

571.  Three  plausible  methods  of  obviating  the  appearance 
of  these  salts  suggest  themselves  : 

First,  to  add  some  chemical  re-aqent  that  will 

Remedies. 

permanently  fix  them  within  the  body  of  the 
mortar  by  converting  them  into  insoluble  compounds. 

Second^  to  render  them  deliquescent  either  before,  or  after 
they  form  those  compounds  that  effloresce. 

Third^  to  saponify  them  by  adding  some  oily  substance. 

672.  Under  the^r^i^  method^  potash  can  be  managed  very  well. 
Hydrofluosilicic  acid  converts  it  into  a  well-known  insoluble 
compound,  while  the  action  upon  the  soda,  if  present,  is  not 
disadvantageous.  Potash,  however,  is  harmless  in  its  effects, 
compared  with  soda.    The  sulphate  of  soda,  likely  to  be  formed 


296 


PRACTICAL  TREATISE  ON  LIMES, 


in  the  vicinity  of  large  cities,  from  the  absorption  of  the  snl 
phuric  acid  gas,  acts  like  frost  in  crystallizing. 

573.  The  second  method  does  not  seem  to  give  promise  of 
success. 

574.  The  third  method^  on  the  contrary,  does  promise  success, 
and  our  trials  under  it  have  been  numerous.  "We  have  found 
it  convenient  to  make  common  lime  the  vehicle  for  conveying 
the  fatty  substance  to  the  cement,  and  here  take  occasion  again 
to  call  attention  to  the  fact  that  lime  paste  may  be  added  to  a 
cement  paste  in  much  larger  quantities  than  is  usually  prac- 
tised in  important  works,  without  any  considerable  loss  of  ten- 
sile strength  or  hardness.  There  is  no  material  diminution  of 
strength  until  the  volume  of  lime  paste  becomes  nearly  equal  to 
that  of  the  cement  paste  (see  Tables  XXX  YII.  and  XXXYIII.), 
and  it  may  be  used  within  that  limit  without  apprehension, 
under  the  most  unfavorable  circumstances  in  which  mortars 
can  be  placed. 

575.  To  secure  a  complete  dissemination  of  the  fatty  matter, 

it  should  be  mixed  up  with  the  caustic  lime,  so 
connection^^  other  phenomena  developed 

in  slaking  will  complete  the  incorporation. 
Its  amount  will  depend  upon  the  proportion  between  the 
cement  and  lime  pastes  in  the  mortar,  and  may  vary  between 
5  and  10  per  cent,  of  the  weight  of  the  quicklime,  when  the 
latter  is  employed  simply  as  a  vehicle. 

576.  In  examining  and  judging  results,  in 

duc\^4tLTiais.    ^^^^^      ^^^i^  apprehended  from 

the  minute  quantity  of  alkali  generally  present 
in  cement,  and  from  the  apparently  precarious  law  which 
seems  to  control  its  appearance  in  the  efflorescent  state,  the 
amount  of  alkali  was,,  in  many  cases,  greatly  increased,  (some- 
times several  hundred  per  cent.,)  by  adding  to  it  from  a  solu- 
tion of  the  salts  taken  from  Fort  Adams.  This  solution  was 
mixed  with  the  water  used  for  making  the  mortar.  With  the 
mortar  thus  prepared,  bricks  were  cemented  together  and  laid 


HTDEAULIC  CEMEOTS,   AND  MORTAES.  29? 


away  in  pairs,  some  of  tliem  being  moistened  occasionally,  and 
others  left  dry.  Cakes  of  the  mortar  not  in  contact  with  brick 
were  also  preserved. 

In  all  cases  where  there  was  any  considerable  excess  of  the 
alkaline  ingredients,  a  plentiful  crop  of  crystals  appeared  on 
the  surface  within  a  day  or  two  after  the  mortar  wag  prepared. 
"No  additional  efflorescence  took  place  after  these  vr ere  removed. 
In  no  case  was  there  any  efflorescence  from  mortar  containing 
the  fatty  substance,  but  to  which  no  saline  ingredients  had 
been  added.  It  is  believed  that  the  proportion  of  the  several 
ingredients  in  practice  should  be  from  8  to  12  pounds  of  the 
fatty  substance  to  100  pounds  of  quicklime,  and  300  pounds  of 
cement  powder.  The  cheapest  kinds  of  animal  fatty  matter 
will  answer. 

577.  It  would  not  be  safe  to  pronounce  at  once  in  favor  of 
this  method  of  remedying  the  evils  of  efflorescence.  It  certainly 
appears  to  give  promise  of  success. 


USTDURATIOK  OF  MORTARS  OF  FAT  LIME. 

578.  We  have  indicated,  paragraph  331,  that  the  hardening 
of  fat  lime  mortars  could  be  partially  attributed  to  the  absorp- 
tion of  carbonic  acid  gas,  producing  carbonate  of  lime  (CaO. 
CO  2).  The  lime  absorbs  only  about  one-half  the  quantity  of  car- 
bonic  acid  (CO2),  necessary  to  convert  the  whole 
into  carbonate  of  lime  ;  or,  in  other  words,  only  ^^^Sfacid!^ 
about  one-half  of  the  lime  becomes  thus  con- 
verted, the  formula  for  the  hydrate  present  being  CaO.COjX 
CaO.H.    But  the  hardening  of  the  fat  lime  mortars  cannot 
be  entirely  attributed  to  the  formation  of  carbonate  of  lime. 
For  we  know  that  mortar,  in  the  centre  of  thick  walls,  which 
never  becomes  carbonated,  nevertheless  possesses  a  fair  degree 
of  adhesiveness  and  hardness.    Some  mortars,  300  years  old, 
examined  in  Dresden  by  Petzholdt,  yielded  a  strong  lime  water 
when  digested  in  fresh  water,  and  must  therefore  have  con- 


298 


PRACTICAL  TEEATISE  ON  LIMES, 


tained  caustic  lime.  Another  portion  of  the  same  mortar  effer- 
vesced freely  with  cold  dilute  muriatic  acid,  and  after  a  few 
minutes  yielded  a  stiff  jelly,  proving  the  previous  combination 
of  lime  and  silica.  Analysis  of  mortars  of  fat  limes  and  sili- 
cious  sand  100  years  old,  and  of  the  limes  which  furnished 
them  were  also  made. 

579.  From  the  experiments  of  Petzholdt,  certain  conclusions 
were  drawn : 

1st.  That  there  was  more  soluble  silica  in  the  lime  mortar 
than  in  the  original  lime. 

2d.  That  there  was  three  times  as  much  soluble  silica  in  the 
raiortar  three  hundred  years  old,  as  in  the  mortar  one  hundred 
years  old,  and  consequently, 

3d.  That  there  must  have  been  a  chemical  combination  be- 
tween the  lime  and  the  silicious  sand. 

4:th.  The  presumption  is  that  the  silicious  compound  formed, 

acted  as  an  indurating  agent. 

But  we  do  not  find  in  these  trials  a  reason 

Mortars  contain-  for  the  induration  of  mortars  containing  none 
ing  calcareous  i       *      i  i 

sand  only.  but  calcareous  sand.    Analyses  do  not  prove 

a  chemical  combination  between  the  lime  and 
the  raw  limestone  composing  this  sand,  and  we  must  therefore 
look  to  the  crystallization  of  the  hydrate  of  lime  during  the 
process  of  desiccation,  for  the  cause  of  the  hardening  in  this 
case. 

580.  The  gang  of  ordinary  lime  mortars  is  a  mechanical 

mixture  of  a  paste  of  hydrate  of  lime  and 
Ordinary  mortar     lime  water,  and   in   drying,   small  crystals 

a  mechanical  />i,it  i         .i  i  t 

mixture,  01  soluble  lime  are  deposited  on  the  adja- 

cent surfaces,  and  adhere  with  such  force  to 
them,  as  to  increase  very  materially  the  strength  of  the  aggre- 
gates, when  the  surfaces  become  closely  approximated,  as  is 
the  case  with  mortars.  In  practice,  the  proportion  of  sand 
would  be  such,  that  the  hydrate  will  form  the  thinnest  possible 
stratum  between  the  grains.    Mortars  containing  a  deficiency 


HYDEAULIC  CEMENTS,  AND  MOKTARS.  299 


of  sand,  indurate  very  slowly.  Wherever  the  soluble  lime 
comes  in  contact  with  air,  or  even  with  water,  carbonic  acid  is 
absorbed,  and  subcarbonates  formed,  which  accounts  for  the 
superior  hardness  of  the  surface  of  mortars.  When  carbonic 
acid  is  thus  absorbed,  its  chemical  equivalent  of  water  escapes 
from  the  hydrate ;  hence  the  dampness  of  newly-built  w^alls, 
and  newly-plastered  rooms.  To  the  foregoing  causes  collec- 
tively, therefore,  to  wit :  the  chemical  formation  of  silicate  of 
lime  and  carbonate  of  lime,  and  the  crystallization  of  the 
hydrate  between  and  upon  the  surfaces  of  the  sand,  we  must 
ascribe  the  solidification  of  common  mortars. 

581.  Mortars  of  common  lime^  suitably  compounded,  "set," 
or  lose  their  plasticity  in  a  very  few  days,  and 
acquire  strensjth  with  such  rapidity,  that  in    Setting  of  mor- 

,  .  ^      ^  TO  1         .  tars  of  commcn 

the  erection  oi  the  largest  edmces,  there  is  no  lime, 
occasion  to  w^ait  for  the  mortar  to  harden. 
They  become  sufficiently  strong  to  resist  a  pow^erful  force  of 
compression  long  before  they  exhibit  any  adhesion  to  the  solid 
materials.    Such  mortars  obtain  their  maximum  strength  and 
hardness  only  after  the  lapse  of  years  and  even  centuries. 


THEOKY  OF  HYDRAULIC  mDURATION. 

582.  The  ingredients  of  hydraulic  limestones  may  be  sepa- 
rated by  analysis  into  two  distinct  classes  of  substances : 
1st.    Ordinary  carbonates  of  lime,  of  mag- 

j     p  J.1         -J  Inarredients  of 

nesia,  and  of  the  oxides.  hydraulic  lime- 

2d.  Various  silicates,  that  is,  combinations 

of  silica  with  alumina,  lime,  magnesia,  the  alkalies,  &c. 

Not  unfrequently,  the  only  ingredient,  except  those  of  the 

first  class,  is  almost  pure  silica. 

In  burning,  the  first  effect  is  to  expel  carbonic  acid ;  the 

second,  to  effect  a  combination  between  the 

lime,  magnesia,  &c.,  thus  liberated,  and  a  por-  burai^^*^°* 

tion  of  the  silicates  or  silica,  producing  com- 


V 


300 


PRACTICAL  TREATISE  ON  LIMES, 


pounds  having  an  excess  of  base,  and  therefore  easily  attacked 
by  acids.  In  fact,  burnt  hydraulic  lines  are  generally  quite 
soluble  in  acids,  leaving  gelatinous  silica.  Another  portion  of 
the  silica  remains  uncombined  until  it  is  brought  into  contact 
with  lime  in  the  presence  of  water,  when  it  unites  with  the 
lime  held  in  aqueous  solution. 

583.  A  lengthy  discussion  of  the  reciprocal  actions  of  the 

several  substances  entering  into  the  composition 
Theory  of  hy-        of  hydraulic  mortars,  which  take  place  during 

draulic  induration      ^      ^        -         ^  •, 

continued.  the  burning  ot  the  stone,  and  the  subsequent 

induration  of  the  mortars,  will  not  be  attempted. 
A  brief  reference  to  the  parts  played  by  the  principal  ingre- 
dients, particularly  the  lime,  magnesia,  silica,  and  alumina, 
would  seem  to  be  required.  The  hydraulicity  of  mortars  is 
the  result  of  combinations  between  these  substances,  effected 
or  commenced  during  the  calcination,  in  the  production  of 
compounds  which  become  hydrated  in  the  presence  of  w^ater, 
and  afterwards  undergo  a  species  of  crystallization,  technically 
termed  "  setting."  The  reactions  begun  by  the  agency  of  heat, 
are  therefore  continued  and  perfected  by  the  .agency  of  water. 

584.  We  will  first  take  a  silicious  lim.estone  for  example, 

capable  of  producing  fair  hydraulic  lime,  as  dis- 
dout nlftot;.     tinguished  from_  cement,  like  many  of  the  beds 

found  in  the  calciferous  sand  rock,  (paragraph  9), 
containing  carbonate  of  lime  in  excess,  and  silica  in  every 
stage  of  subdivision,  ordinarily  found  in  fine  quartzose  sand. 
If  the  several  ingredients  are  homogeneously  mixed  in  the  raw 
stone,  a  proper,  that  is  to  say,  a  complete  calcination  of  this 
stone  results  in  a  combination  of  all  the  silica,  not  in  the  state 
of  inert  sand,  with  its  equivalent  of  lime.  The  resulting  hy- 
draulic lime  will  contain  free  caustic  lime,  inert  sand,  and  a 
silicate  of  lime,  of  which  the  formula  in  the  general  case  will 
be  SiOs.SCaO.  The  hydraulic  virtue  of  this  variety  of  lime  is 
derived  in  a  great  measure  from  this  silicate.  When  mixed 
into  a  paste  with  fresh  water,  the  silicate  combines  with  six 


HYDEAULIC  CEMENTS,  AND  MORTARS. 


301 


equivalents  of  that  substance,  producing  the  hydrosilicate  ol 
lime  (SiOs.CaO+^HO).  All  our  experience  and  researches 
go  to  prove  that  silica  plays  a  most  important  part  in  the 
solidification  of  hydraulic  limes  and  cements,  and  that  the  de- 
gree of  hardness  attained  depends  on  the  molecular  condition 
of  the  silica,  and  the  amount  of  base  which  ultimately  com- 
bines with  it.  In  the  formation  of  silicate  of  lime,  the  limit  of 
saturation  should  never  be  reached,  for  this  requires  two 
equivalents  of  silicic  acid  (silica)  to  three  of  lime  (2Si03.3CaO), 
and  contains  .48  of  lime  and  .52  of  silica — a  compound  pos- 
sessing no  hydraulicity  at  any  stage  of  calcination,  and  con- 
taining double  the  proportion  of  silica  deemed  most  advan- 
tageous for  mortars.  From  analyses  of  mortars  of  the  Theil 
hydraulic  lime,  it  was  discovered  that  the  hydrosilicate  con- 
tained .25  of  silica,  .47  of  lime,  and  .28  of  water.  Besides  the 
silicate  of  lime  formed  during  the  calcination,  there  is  another, 
formed  by  a  transfer  of  soluble  lime  to  the  silica,  which,  from 
the  heterogeneous  character  of  the  stone,  does  not  combine 
under  the  influence  of  heat. 

585.  If  the  limestone  contains  alumina  in  addition  to  the 
sHica,  or,  in  other  words,  if  clay  be  one  of  its  constituent  ele- 
ments, in  proportions  suitable  for  ordinary  hy-  reactions 
draulic  lime,  carbonate  of  lime  still  being  in    when  alumina  is 
excess,  the  reactions  which  take  place  during 
the  calcination  and  the  quality  of  the  resulting  product  will 
depend  on  the  intensity  and  duration  of  the  heat.    When  this 
is  simply  sufficient  to  expel  all  the  carbonic  acid,  a  separate  and 
independent  combination  of  lime  with  silica  and  alumina  takes 
place  during  the  burning,  producing  silicate  and  aluminate  of 
lime,  both  of  which  become  hydrated  by  taking  up  six  equiva- 
lents of  water.    The  resulting  hydrosilicates  are  represented 
by  the  formulas 

Si03.3CaO+6HO,  and 
A103.3CaO-}-6HO. 


302 


PRACTICAL  TREATISE  ON  LIME8, 


Syntlielical  experiments  appear  to  indicate  that  the  ahimin- 
ate  is  the  least  stable  of  these  two  substances. 

586.  If  loe  vary  the  conditions  of  calcination  in  the  last 
Effect  of  augment-  mentioned  case,  by  augmenting  the  intensity 
ing  intensity  and     and  duration  of  the  heat  to  that  degree  neces- 

duration  of  heat.  .  ^ 

sary  to  cause  partial  vitrmcation  of  some  por- 
lions,  but  not  of  all,  the  product  becomes  heterogeneous.  In 
those  23ortions  burnt  the  most,  the  silica,  alumina,  and  lime  are 
combined  together  by  the  heat  under  certain  reactions  that  at 
present  appear  to  be  rather  obscure.  This  is  more  especially 
the  case,  when  other  substances  are  present,  which  may  aet  as 
fluxes.  MM.  Chatoney  and  Rivot  incline  to  the  opinion  that 
the  silicates  of  alumina  and  of  lime  are  both  formed,  and  that 
these  compounds,  in  the  presence  of  water,  are  decomposed, 
the  results  being  aluminate  and  silicate  of  lime,  which  become 
hydrated  by  combining  with  three  equivalents  of  water.  In 
that  case,  the  formula  for  these  compounds  will  be  Al.Oa.SCa 
0-f  3H0  and  Si03.3CaO+3HO.  The  fact  that  these  chemical 
reactions  require  for  their  completion  only  half  as  much  water 
as  when  the  heat  is  less  intense  during  the  burning,  may  be 
intimately  connected  with  the  superior  hardness  of  some  of  the 
gangs  made  from  vitrified  cement. 

In  those  portions  least  burnt,  the  aluminate  and  silicate  of 
lime  are  separately  formed  by  the  action  of  heat,  and  these 
combine  directly  with  6  HO,  as  in  paragraphs  584  and  585. 

587.  If  we  suppose  the  clay  to  he  in  excess  in  the  limestone, 

as  is  orenerally  the  case  with  marls,  a  moderate 

The  reactions  .  ^  .  ,     ,  ,  . 

when  the  clay  is  burning,  just  sumcient  to  expel  the  carbonic 
in  excess.  acid,  causes  a  separation  between  the  alumina 

and  silica  of  the  clay,  the  alumina  remaining  practically^  inert, 
while  the  silica  combines  with  the  lime,  producing  SiOs.SCaO. 
This  becomes  hydrated  by  taking  up  six  equivalents  of  water, 
producing  a  hydrated  silicate  of  the  same  composition  as  that 
recorded  in  paragraphs  584  and  585.  A  high  heat  produces 
rather  complicated  and  obscure  reactions  on  this  class  of  sub- 


HYDIIAULIC  CEMENTS,  AKD  MOETAES. 


303 


stances.  A  partial  triple  combination  of  alumina,  silica,  and 
lime  takes  place  during  the  burning,  and  the  compounds  thus 
formed  become  hydrated  under  conditions  not  very  tlioroughly 
understood. 

588.  The  setting  of  mortars  of  fat  lime  and  pozzuolana,  natu- 
ral or  artificial,  is  likewise  due  to  the  formation 

of  hydrated  compounds  of  lime  with  silica  and  fnTpoLuofan^^^ 
alumina.    The  lime  attacks  the  silica  and  alu- 
mina, freeing  them  from  previous  combinations,  when  such 
exist,  and  slowly  forms  with  them  SiOa.SCaO,  and  AI2O3. 
3CaO. 

589.  It  has  been  recommended  to  allow  these  mortars  to 
remain  mixed  for  some  time,  before  temperino* 

.  .  .  To  remain  mixed 

them  just  previous  to  use,  a  precaution  which  some  time  before 
rests  upon  a  plausible,  and  doubtless,  a  sound  *®°^P®"^^'^r 
theory  ;  for  while  the  combinations  of  lime  with  silica  and 
alumina  previously  exist  in  the  hydraulic  limes  and  cements, 
(having  been  formed  during  the  calcination  and  are,  therefore, 
in  condition  to  become  hydrates  at  once,  in  presence  of  water,) 
the  conditions  are  quite  different  with  mortars  of  fat  lime  and 
pozzuolana,  in  which  the  silica  and  alumina  have  to  first  free 
themselves  from  combinations  peculiar  to,  and  existing  in  the 
pozzuolana  before  they  can  form  in  the  wet  way  those  com- 
pounds, which  afterwards  become  hydrates,  and  confer  hydrau- 
licity.  From  this  we  can  comprehend  why  fat  lime  should  be 
used  in  preference  to  hydraulic  lime  for  pozzuolana  mortars, 
since  the  compounds  formed  during  the  burning  of  hydraulic 
lime  will  have  become  hydrates,  and  will  have  initiated  the 
hydraulic  set,  before  those  formed  in  the  wet  way  between  the 
free  caustic  lime  and  the  pozzuolana  will  have  completed  the 
preliminary  decomposition  :  and  because,  for  the  same  reason, 
if  we  employ  hydraulic  lime,  it  is  only  the  excess  of  caustic 
lime  in  it  that  combines  advantageously  with  the  pozzuolana. 
The  operation  in  the  mortar  of  two  dissimilar  powers,  one  cmii- 
posmg^  and  the  other  decomposing  in  character,  might  operate 


304 


PRACTICAL  TREATISE  ON  LIMES, 


disadvantageously.  The  conditions  should  be  such,  that  the 
difierent  combinations  of  the  lime  with  the  silica  and  alumina, 
no  matter  how,  when,  or  where  formed,  should  become  hy- 
drated  simultaneously. 

590.  Magnesia  plays  an  im^portant  jpart  in  the  setting  of 
.  ,.     p  mortars  derived  from  the  ar^iillo-mao^nesian 

Action  01  magne-  ci  ?3 

sia  on  the  setting    limestones,  such  as  those  w^hich  furnish  the 

of  cements.  -r»         i  i  mi  .     im  i 

Kosendale  cements.  ihe  magnesia,  like  the 
lime,  appears  in  the  form  of  the  carbonate  (MgO.COs).  During 
calcination,  the  carbonic  acid  (CO2)  is  driven  off,  leaving  prot- 
oxide of  magnesia  (MgO)  which  comports  itself  like  lime  in  the 
presence  of  silica  and  alumina,  by  forming  silicate  of  magne- 
sia (SiOo.SMgO)  and  aluminate  of  magnesia  (AlgOg.SMgO). 
These  compounds  become  hydrated  in  the  presence  of  water, 
and  are  pronounced  by  both  Yicat  and  Chatoney  to  furnish 
gangs  which  resist  the  dissolving  action  of  sea-water  better 
than  the  silicate  and  aluminate  of  lime.  This  statement  is 
doubtless  correct,  for  we  know  that  all  of  those  compounds, 
whether  in  air  or  water,  absorb  carbonic  acid,  and  pass  to  the 
condition  of  subcarbonates,  and  that  the  carbonate  of  lime  is 
more  soluble  in  water  holding  carbonic  acid,  and  certain  or- 
ganic acids  of  the  soil  in  solution,  than  the  carbonate  of  mag- 
nesia. At  all  events,  whatever  may  be  the  cause  of  the  supe- 
riority, it  is  pretty  well  established  by  experience,  that  the  ce- 
ments derived  from  the  argillo-magnesian  limestones  furnish  a 
durable  cement  for  constructions  in  the  sea.  In  Marshal 
Yaillant's  report  to  the  French  Academy  of  Sciences,  from  the 
Commission  to  which  MM.  Ohatoney  and  Rivot's  paper  was 
referred  in  1856,  this  superiority  of  the  magnesian  hydrates  is 
distinctly  asserted  ;  but  the  Commission  appear  to  have  been 
led  to  erroneous  inferences  in  regard  to  the  conditions  under 
which  it  is  expedient  or  possible  to  take  advantage  of  this  prop- 
erty. We  quote  from  the  first  part  of  their  report,  as  follows : 

"  On  pourrait  en  conclure  qu'il  serait  utile  de  remplacer  la 
chaux  par  la  magnesie  pour  fabriquer  les  mortiers  hydrau- 


HYDRAULIC  CEMENTS,  AKD  MOETARS.  305 


liqnes ;  mais  la  magnesie  n'est  pas  assez  repandue  dans  la  na- 
ture pour  qu'on  puisse  i'employer  a  1' exclusion 
de  la  chaux  dans  les  constructions  a  la  mer.  ^^n'ya^Lnt'" 
En  tout  cas,  il  faut  proscrire  avec  soin  le  mel- 
ange de  ces  bases,  c'est-a-dire  I'emploi  des  calcaires  magnesiens, 
attendu  que  les  silicates  et  aluminates  formes  par  la  magnesie 
ne  s'hjdratent  pas  avec  la  meme  vitesse  que  ceux  formes  par  la 
chaux,  et  qu'ils  risquent  d'ailleurs  d'etre  partiellement  decom- 
poses apres  I'immersion  par  la  chaux  restee  en  exces,  si  le  me- 
lange n'a  pas  ete  longtemps  digere  au  prealable  dans  une  faible 
quantite  d'eau.    En  d'autres  termes,  ces  mortiers  ne  presentent 
aucune  homogeneite,  aucune  chance  de  stabilite  dans  la  prise." 

It  is  needless  to  say  that  the  "  careful  proscription"  of  "mag- 
nesian  limestones"  so  forcibly  inculcated  in  this  quotation  is 
altogether  too  comprehensive.  While  we  are  not  prepared  to 
say  that  the  double  carbonate  of  lime  and  magnesia,  called 
dolomite,  containing  a  single  equivalent  of  each  of  the  bases, 
although  eminently  hydraulic,  could,  in  practice,  be  relied  upon 
for  hydraulic  mortars,  even  in  localities  where  the  supply  is 
sufficiently  abundant  for  such  a  purpose,  yet  it  is  certain,  that 
many  magnesian  limestones,  especially  those  which  contain 
clay,  do  furnish  good  cements,  and  that  the  Rosendale  brands, 
our  chief  and  best  reliance  in  the  United  States,  are  derived 
from  this  class,  and  ai-e  by  no  means  open  to  the  objection  ad- 
vanced above,  viz. :  that  they  offer  "  neither  homogeneousness 
nor  chance  of  stability  in  setting."  Some  portions  of  the  de- 
posit of  Rosendale  cement  stone  contain  as  high  as  .39  of  car- 
bonate of  magnesia  to  .40  of  carbonate  of  lime;  others,  as  low 
as  .1448  of  carbonate  of  magnesia,  to  .2848  of  carbonate  of 
lime.  Between  these  extremes  are  found  numerous  interme- 
diate proportions. 

591.  Kecent  analyses  of  American  cements  . 

American  ce- 

show  that  they  all  contain  more  or  less  of  the    ments  contain 
alkalies,  sometimes  caustic  and  sometimes  in  the 
form  of  chlorides  of  sodium  and  potassium.    The  chlorides  are 
20 


306 


PEACTICAL  TREATISE  ON  LIMES, 


present  in  all  the  Rosen  dale  cements,  as  well  as  in  those  from 
Shepherdstown,  Virginia,  and  Akron,  Erie  Co.,  New  York. 
The  alkalies  promote  hydraulic  induration  in  their  own  pecu- 
liar way.  We  know  that  mortars  of  American  cements  part 
with  soda  and  potash  when  immersed  in  water,  and  render  the 
latter  alkaline;  and  that  alumina  and  gelatinous  silica  are 
soluble  in  potash  ;  also  that  a  solution  of  an  alkaline  silicate 
readily  gives  np  its  silica  to  lime.  We  may  therefore  presume 
that  the  alkalies,  particularly  the  potash,  act  by  first  dissolv- 
ing the  silica  and  then  transferring  it  to  lime,  at  the  same 
time  that  the  water  acts  by  dissolving  the  lime  and  carrying 
it  to  the  silica. 

Wlien  the  silica  is  592.  When  the  silica,  present  in  suitable  form 
m  excess.  ^-^^  entering  into  combination,  is  in  excess  of  the 

equivalent  required  by  the  lime  and  magnesia,  the  proportion 
should  be  adjusted  in  practice,  as  far  as  possible,  by  adding 
paste  of  fat  lime,  otherwise  the  mortar  will  be  deficient  in 
strength  and  liable  to  crack.  Several  prisms  (2"x2"x8") 
were  made  of  the  paste  of  J  ames  Kiver  cement  without  sand, 
atid  kept  in  water  until  they  were  320  days  old.  This  cement 
contains  nearly  fifty  per  cent,  of  silica,  although  the  analysis 
does  not  state  in  what  form  it  exists.  Some  of  the  prisms 
broke  in  handling.  They  were  all  covered  over  more  or  less 
with  cracks,  were  quite  brittle,  and  ranged  rather  above  the 
average  hardness  of  mortars  of  pure  cement  paste  as  shown 
by  the  penetration  of  the  needle.  On  supports  4"  apart  those 
that  remained  whole  gave  an  average  breaking  weight  of  346 
lbs.  The  fracture  was  quite  jagged  and  angular,  although 
each  of  the  small  surfaces  composing  it  was  in  itself,  compara- 
tively smooth  and  conchoid al.  The  first  impact 
of  the  needle  split  most  of  the  prisms,  and  none 
of  them  withstood  the  second.  When  the  block 
did  not  split,  the  effect  of  the  first  impact  was  to 
raise  up  the  mortar  in  thin  scales  around  the 
needle.  Tig.  56. 


HYDRAULIC  CEMENTS,  AND  MORTARS.  307 


The  general  appearance  of  the  fraction  is  given  in  Figs.  56 
and  57. 

ISTone  of  the  prisms  left  in  the  air  conduct- 
ed themselves  in  this  peculiar  way,  although 
they  gave  low  breaking  weights,  the  average 
being  only  330  lbs. 

A  paste  of  this  cement  is  improved  by  the 
addition  of  lime  paste,  up  to  the  limit  of  75  to 
100  per  cent.    Inert  silica  in  cement  acts 
simply  as  an  adulterating  agent,  and  takes  the  place  of  so 
much  sand. 


THE  HARDE^^IKG,  BY  ARTIFICIAL  MEAISTS,  OF 
STONE,  BEICK,  MORTAR,  &c. 

593.  "Within  the  last  twelve  or  fifteen  years,  the  attention  of 
engineers  and  architects  has  been  directed,  in  a  manner  more 
than  usually  active,  particularly  in  Europe,  to  the  destructible 
character  of  many  of  the  materials  in  most  common  use  for 
the  walls  of  constructions  of  all  kinds.  The  consequence  is, 
that  a  variety  of  methods  have  been  devised,  and  to  a  limited 
extent  practised,  for  increasing  their  durability. 

594.  -No  material  will  retain  through  a  long  The  hardest  stone 
series  of  vears  the  same  appearance  as  when    liable  to  gradual 

"  decay. 

fresh  from  the  hands  of  the  workman.  Even 
the  hardest,  most  solid  and  compact  rocks,  such  as  granite, 
sienite,  gneiss  and  the  densest  silicious  rocks,  exhibit  after  long 
exposure,  indubitable  evidences  of  "  weathering  while  many 
buildings  erected  within  the  last  quarter  of  a  century,  of 
some  varieties  of  the  limestone,  marble,  and  sandstone  of 
this  country,  the  Bath,  Reigate,  and  Caen  stone  of  the  British 
Isles,  and  their  corresponding  formations  on  the  continent  of 
Europe,  are  already  in  an  advanced  state  of  decay. 
695.  Of  all  the  causes  of  progressive  destructibility  in  stoiie 


808  PEAOTICAL  TREATISE  O^^  LEVIES, 

Alternations  of  ^^^^  more  active  or  more  difficult  to  guard 
heat  and  cold,  a  against,  than  frequent  alternations  of  heat  and 
cold,  and  of  moisture  and  dryness.  However 
slight  a  change  of  temperature  may  be,  all  bodies  will  expand 
when  it  is  raised,  and  contract  when  it  is  lowered,  although 
some,  even  among  different  kinds  of  stone,  are  much  more  sen- 
sitive to  those  variations  than  others.  In  the  United  States, 
the  thermometer  will  vary  110  to  120  degrees  between  the 
severe  frosts  of  winter  and  the  direct  rays  of  the  summer's  sun  ; 
extremes  which,  operating  in  conjunction  with  the  presence  of 
moisture  in  the  pores  of  the  solid  body,  alternating  not  only 
with  the  seasons,  but  oftentimes,  especially  in  the  winter,  with 
the  recurrence  of  night  and  day,  between  the  opposite  condi- 
tions of  water  and  ice,  cannot  but  result  in  a  change  in  the  state 
of  aggregation  of  the  body,  and,  if  the  latter  be  more  than  or- 
dinarily porous,  in  serious  disaggregations  near  the  surface. 
This  will  be  more  especially  the  case,  if  the  mass  be  made 
up  of  several  substances  of  different  specific  gravities,  and  of 
unequal  capacity  for  resisting  the  expanding  power  of  heat. 

596.  The  methods  devised  for  increasing  the  durability  of 
stones,  hricks,  tiles,  &c.,  are  doubtless  equally  well  adapted  to 
mortar  work,  such  as  exterior  stucco  or  concrete,  and  may 
with  propriety  be  noticed  here.  In  fact,  those  modes  which 
now  give  the  best  promise  of  efficacy, 'base  their  claims  to  pub- 
lic support,  in  a  great  measure,  upon  their  alleged  applicability 
to  such  purposes,  particularly  to  the  restoration  of  monuments, 
statuary,  interior  and  exterior  ornamentation,  &c. 

597.  The  methods  of  artificial  induration  are  reduceable  to 
The  general       tWO,  as  follows  : 

methods  of  artifi-       First.  By  means  of  those  mixtures  or  solu- 

cial  induration.  .  i  .  i        i     i  t    i  i  /. 

tions,  which,  whether  applied  to  the  suriace 
with  a  brush  like  paint  or  oil,  or  by  immersing  the  solid  body 
in  them  for  a  longer  or  shorter  time,  act  simply  as  mechanical 
protectives  against  the  penetration  of  moisture,  by  forming 
either  an  impervious  coating  upon  its  surface,  or,  by  penetrat- 


HYDEAULIC  CEMENTS,  AND  MORTAES.  309 


ing  to  a  greater  or  less  depth,  close  up  the  pores,  and  render 
it  non-absorbent. 

Second.  By  means  of  those  aqueous  solutions,  which  possess 
the  properties  of  reagents,  and  which,  when  entering  the  inter- 
stices of  the  solid,  give  rise  to  certain  chemical  reactions  by 
combining  with  it,  or  with  other  and  different  solutions  ap- 
plied before  or  after,  whereby  insoluble  solids  are  produced,  and 
the  density  and  hardness,  and  consequently  the  durability  and 
strength  of  the  solid  are  increased. 

698.  Among  the  first  class  may  be  noticed  Examples  belongs 
a  patent  "  for  indurating  and  preserving  stone,-'  ing  to  the  first 
granted  in  England  in  1847.  The  stone  to  be 
operated  upon  was  first  dressed  to  the  required  form,  and  then 
thoroughly  dried  in  a  heated  chamber,  or  by  some  other  suita- 
ble contrivance,  to  drive  off'  the  moisture.  The  solution,  com- 
posed of  resin  dissolved  in  turpentine,  oil,  wax,  tallow,  or  some 
other  fatty  substance,  being  brought  to  the  boiling  point  in  a 
vessel  of  the  requisite  dimensions,  is  retained  at  that  tempera- 
ture while  the  stone  is  immersed  in  it.  Ordinarily,  two  hours' 
boiling  has  been  found  sufficient  to  impregnate  the  stone  to 
the  depth  of  one  inch. 

A  similar  process  was  patented  in  England  in  1853,  in  the 
application  of  which  it  is  recommended  to  operate  upon  the 
stone  in  air-tight  chambers,  exhausted,  or  partially  so,  of  the 
air,  by  wdiich  means  a  more  thorough  impregnation  of  the 
material  is  secured. 

Several  varieties  of  indurating  mixtures  were  recommended 
by  the  patentee,  only  two  of  which  we  will  give.  The  first  is 
composed  of  resin  dissolved  in  naphtha,  turpentine,  or  spirits  of 
wine,  mixed  with  gutta  percha  dissolved  in  coal-tar  naphtha, 
and  when  heated,  mixed  still  further  with  some  kind  of  oil, 
after  whicli  w^ell  pulverized  "  anti-corrosia"  is  added.  Another 
mixture  is  made  from  unslaked  lime,  to  which  is  added,  whilst 
slaking,  oil,  or  soap  fat,  and  Eussia  tallow.  When  the  slaking 
is  completed,  the  whole  is  placed  in  a  vessel  with  alum  water, 


aio 


PRACTICAL  TEEATISE  ON  LIMES, 


pulverized  "  anti-corrosia,"  and  proto-sulphate  of  iron,  and  a 
solution  made  from  potatoes  and  beer  settlings.  After  settling, 
the  solution  is  decanted  for  use. 

Another  patented  process  consists  in  the  repeated  applica- 
tion, with  a  brush,  of  a  solution  of  bee's  wax  in  coal-tar  naph- 
tha, which  is  varied  when  the  natural  color  of  the  stone  is  to 
be  preserved,  to  white  wax  dissolved  in  double  distilled  cam- 
phene. 

599.  Without  discussing  the  respective  merits  of  these 
First  method  not  ^^ethods,  we  will  simply  suggest  that  no  process 
practicable  al-  of  indurating  and  preserving  stone,  that  re- 
^^^^  quires  the  handling  and  removing  of  heavy 
masses,  will  ever  be  likely  to  reach  an  extensive  application  in 
the  United  States.  The  characteristic  impetuosity  of  our  peo- 
ple, the  very  active  competition  existing  in  all  departments  of 
industry,  and  the  low  scale  of  prices  to  which  this  state  of 
things  has  given  birth,  excludes  the  idea  that  any  slow,  plod- 
ding, and  costly  method,  however  valuable  and  efficacious  for 
attaining  a  desirable  end,  can  enter  into  successful  competition 
with  one  that  is  more  rapid,  less  expensive,  and  easy  of  appli- 
cation. It  is  also  unlikely  that  any  plan  for  indurating  and 
preserving  architectural  stonework,  that  cannot  be  advan- 
tageously executed  without  complicated  appliances,  and  aftei 
the  building  is  erected,  will  ever  become  of  any  practical  utili 
ty  ;  and  it  is  equally  unlikely  that  any  solution  of  resin,  wax,  or 
like  substances  in  the  fixed  or  essential  oils,  which,  whether 
applied  hot  or  cold,  merely  remain  mechanically  interposed  in 
the  interstices  of  the  solid  body,  can  ever  furnish  other  than  a. 
temporary  protection. 

600.  The  methods  of  preservation  which  belong  to  the  second 

Examples  belong-  ^^^^^^        indurating  media  are  ap- 

ing to  the  second  plied  in  the  condition  of  an  aqueous  solution, 
method. 

possessmg  reacting  powers,  rest  upon  a  more 
scientific  basis,  and  are  essentially  different  from  those  referred 
to  abovn.     Mr.  Fred.  Ransome  gives  the  following  particu- 


HYDRAULIC  CE:.IEIS[TS,  AND  MORTARS. 


3H 


(ars  of  a  process  for  whicli  he  procured  a  pat-    Ransome's  pro- 

C6SS. 

ent  in  England  :  It  "  consists  in  the  employ- 
ment of  two  or  more  separate  solutions,  which,  by  mutually 
acting  upon  each  other,  produce  within  the  pores  of  the  stone 
an  indestructible  mineral  precipitate.  In  operating,  the  stone, 
may  either  be  immersed  in,  or  saturated  on  the  surface  with 
a  weak  solution  of  silicate  of  soda  or  potash,  and  afterwards 
with  a  solution  of  chloride  of  calcium  or  barium,  when  an 
insoluble  silicate  of  lime  or  baryta  is  formed  in  the  pores 
of  the  stone,  rendering  it  impervious  to  moisture,  and  in- 
susceptible of  injurious  effects  from  atmospheric  influences. 
Or,  instead  of  a  silicate  of  potash  or  soda,  a  solution  of  sul- 
phate of  alumina  may  be  employed,  and  then,  by  an  applica- 
tion of  baryta,  a  compound  of  sulphate  of  barytes  and  alumina 
is  formed." 

This  process,  although  apparently  closely  re-  ^  Kuhimann's 
sembling  that  recommended  by  Professor  Fred,  general  process. 
Kuhlmann,  of  Lille,  briefly  referred  to  in  paragraph  551,  difiers 
from  it  in  the  important  particular  of  its  alleged  adaptation  to 
all  kinds  of  stone,  and  of  using,  in  all  cases,  two  solutions  in- 
stead of  one,  the  increase  of  density  of  the  stone  operated  upon, 
being  due  to  the  solid  compound  formed  by  the  mutual  decom- 
position of  the  two  fluids  employed  ;  whereas  M.  Kuhlmann 
recommends  his  process  of  silicatization  to  the  hardening  of 
soft  limestones  and  marble,  whether  in  the  walls  of  buildings 
or  in  the  form  of  monuments,  ornamentation,  or  statuary,  tO; 
calcareous  mortars  of  all  kinds,  and  to  all  works  of  whatevei 
character  made  of  plaster,  such  as  mouldings,  casts,  &c. 

601.  The  following  extract  is  taken  from  the  "  Report  of  the 

Commission  chargied  by  the  Minister  of  Am- 

1  ^  1  V»     1.   ^    1  11        Report  of  Corn- 

culture,  Commerce,  and  Public  W  orks,  with  the    mission  on  Kujil- 

examination  of  M.  Kuhimann's  processes  of  sili-    ^^^^  ®  process, 
catization." 

"  The  liquo7'  of  flints — silicate  of  potash  or  silicate  of  soda- 
is  the  base  of  the  new  process.    As  far  back  as  the  year  1840, 


312 


PEACTICAL  TREATISE  ON  LIMES, 


some  examination  into  the  origin  and  nature  of  the  efflores- 
cences on  walls,  had  given  M.  Kuhlmann  an  opportunity  to 
establish,  beyond  doubt,  the  presence  of  potash  and  of  soda  in 
most  of  the  limestones  of  all  geological  epochs,  in  larger  pro- 
portions in  the  hydraulic  limestones  than  in  those  suitable  for 
common  lime.  What  influence  can  they  exert  upon  the  hy- 
draulic property  ?  M.  Kuhlmann  is  of  the  opinion  that,  under 
the  influence  of  carbonate  of  potash  or  of  soda,  the  silicious 
limestones  give  rise  by  calcination,  to  double  combinations  of 
lime,  of  silica,  or  alumina,  with  an  alkali,  analogous  to  those 
obtained  by  the  calcination  of  some  species  of  hydrated  mine- 
rals, such  as  the  apophyllite,  the  stilbite,  and  the  analcime; 
that  these  compounds,  subsequently  put  in  contact  with  water, 
undergo  a  reaction  analogous  to  that  which  causes  the  consoli- 
dation of  sulphate  of  lime,  viz. :  a  hydration,  and  as  a  conse- 
quence thereof,  an  induration. 

"  The  principal  eflfect  produced  by  the  potash  and  the  soda, 

is  to  convey  a  certain  portion  of  silica  to  the 
^h^and^soda!'^*"    Hmo,  giving  birth  to  silicates,  which,  while  they 

absorb  the  water  with  avidity,  retain  only  such 
quantity  of  it  as  is  necessary  for  their  composition  as  hydrates, 
and  for  their  induration.  Numerous  facts  support  this  theory : 
fat  lime,  placed  in  contact  with  a  solution  of  silicate  of  potash, 
is  immediately  transformed  into  hydraulic  lime ;  mortars  of  fat 
lime,  injected  several  times  with  a  solution  of  alkaline  silicates 
are  transformed  into  hydraulic  mortars ;  lastly,  with  the  vitre- 
ous alkaline  silicate,  and  lime  more  or  less  energetic,  hydraulic 
cements  can  be  produced,  which  can  be  utilized  in  localities 
where  none  but  fat  lime  is  found  in  the  quarries. 

602.  Silicatization. — M.  Kuhlmann^  by  noticing  the  great 
aflinity  of  lime  for  silica,  left  free  in  the  nascent  state,  from  its 
combination  with  potash,  was  also  led  to  study  the  action  of  the 
silicates  of  potash  and  of  soda  upon  the  soft  limestones  and 
chalk.  He  noticed  the  fact,  that  if  chalk  is  placed  in  contact, 
at  the  ordinary  temperature,  with  a  solution  of  silicate  of  pot 


HYDEAULIC  CEMENTS,  AND  MOETAES.  313 


ash,  it  is  partially  changed  into  a  silicio-carbonate  of  lime, 
while  a  corresponding  portion  of  potash  is  displaced  ;  that  the 
chalk  gradually  hardens  in  the  air,  and  becomes  harder  than  the 
best  hydraulic  cements  ;  that  the  same  chalk,  made  into  a  paste 
with  the  silicate,  possesses  the  property  of  strongly  adhering  to 
the  surface  of  bodies  on  which  it  is  applied.  He  has  thereby 
discovered  a  mastic  suitable  for  the  restoration  of  public  mon- 
uments, and  for  the  fabrication  of  works  of  moulding.  Carry- 
ing his  experiments  still  further,  he  found  that  the  chalk,  in 
the  state  of  rock  as  found  in  nature,  if  repeatedly  immersed  in 
a  solution  of  silicate,  and  alternately  exposed  to  the  action  of 
the  atmosphere,  is  capable  of  absorbing  a  considerable  quantity 
of  silica,  and  after  some  time  acquires  great  hardness  on  its 
surface;  that  the  induration,  at  first  superficial,  penetrates  by 
degrees  towards  the  centre,  so  much  so  that  a  sample,  experi- 
mented upon  fifteen  years  previously,  and  placed  before  the 
Commission  for  inspection,  had  acquired  that  induration  to  a 
depth  of  nearly  one  centimetre  (.39  in.)  This  "  silicatization," 
as  M.  Kuhlmann  styles  his  process,  is  due  to  the  decomposition 
of  the  silicate  of  potash,  partly  by  the  carbonate  of  lime,  and 
partly  by  the  carbonic  acid  of  the  air.  A  solution  of  silicate 
of  potash  left  in  the  air,  will,  in  effect,  after  some  time,  form  a 
gelatinous  «,iid  contractible  deposit  of  silica,  and  a  layer  of  car 
bonate  of  potash.  The  deposit  of  silica  acquires,  after  some 
time,  a  hardness  sufficient  to  scratch  glass.  Of  two  balls  of 
chalk  of  the  same  size  and  quality,  both  silicatized  in  the  same 
manner,  the  one  left  in  the  open  air  acquires  a  greater  hard- 
ness than  the  other  placed  under  a  glass  receiver,  where  the 
air  is  free  from  carbonic  acid.  By  this  process,  therefore,  there 
is  formed  a  kind  of  a  hydrated  silicio-carbonate  of  lime,  which 
indurates  while  gradually  abandoning  its  water  of  hydration, 
and  a  contractible  deposit  of  silica,  which  also  augments  the 
hardness  of  the  stone.  The  carbonate  of  potash  produces  on 
the  surface  a  perceptible  exudation  or  efflorescence,  which  de- 
creases by  degrees,  and  at  last  totally  disappears,  without  hav- 


314 


PRACTICAL  TREATISE  ON  LIMES, 


ing  altered  the  surface  in  any  manner.  By  means  of  the  hy- 
drofluo-silicic  acid,  M.  Kuhlmann  has  succeeded  in  obviating 
the  inconveniences  that  may  arise  therefrom,  while  he  at  the 
same  time  increases  the  progressive  induration 

"  Calcareous  stones  thus  prepared  assume  a  compact  texture, 
a  smooth  appearance,  and  are  capable  of  receiving  a  fine  polish. 
The  induration  is  singularly  favored  by  heat.  Some  porous 
limestones,  immersed  in  a  boiler,  under  a  high  pressure,  con- 
taining a  bath  of  silicate  of  potash,  assumed  soon  after  removal 
all  the  characters  of  compact  silicio-calcareous  stones,  without 
the  slightest  intervention  of  the  carbonic  acid  of  the  air. 

603.  M.  Kuhlmann  experimented  upon  other  porous  stones^ 
and  observed  that  the  action  of  the  carbonic  acid  of  the  air  upon 
silicate  of  potash,  was  sufficient  to  cause  on  the  surface  of  the 
stones  a  consolidation  varying  in  intensity  with  their  porosity. 

604.  Upon  the  sulphate  of  lime  or  plaster,  the  action  is  sen- 

sibly the  same,  but  is  more  rapid,  and  possesses 

Action  on  sul-  .  .  p    .   .  . 

phate  of  lime.  the  mconvenience  oi  giving  rise  to  sulphate  of 
potash,  which,  by  crystallizing,  has  the  property 
of  disaggregating  the  surfaces.  In  this  case  the  solution  must 
be  more  diluted,  in  order  to  secure  a  slower  action,  although 
producing  a  sufficient  consolidation  for  avoiding  the  effects  of 
the  crystallization  of  the  sulphate  of  potash. 

605.  "  Mode  of  appliGation. — The  solution  of  the  silicate  of 
potash,  as  manufactured  by  M.  Kuhlmann  for  the  market,  is 
quoted  at  35°  by  Beaume's  areometer.  It  is  sufficient  to  dilute 
it  in  twice  its  volume  of  water,  in  order  to  obtain  the  degree  of 
concentration  most  suitable  for  induration.  Upon  recent  con- 
structions, the  application  can  be  made  without  preparation ; 
on  old  ones,  it  is  preceded  by  a  thorough  washing  of  the  surface, 
using  for  this  purpose  a  hard  brush  dipped  in  a  dilute  solution 
of  caustic  potash.  Upon  large  surfaces,  the  applications  are 
made  with  force-pumps  or  syringes,  care  being  taken  to  collect, 
by  means  of  ridges  made  of  potter's  clay,  at  the  foot  of  the  wall, 
the  liquid  in  excess.    For  sculptures  and  certain  portions  of 


HYDRAULIC  CEME^^TS,  AND  MOETAES. 


315 


buildings,  soft  brushes,  or  more  advantageously  pencils,  are 
made  use  of.  Experience  has  shown  that  three  applications 
made  during  three  days  consecutively,  are  sufficient  to  properly 
harden  the  stone.  The  quantity  of  solution  absorbed  varies  with 
the  nature  and  porosity  of  the  stone  ;  the  cost  of  the  silicate 
never  reaches  above  75  centimes  per  square  metre  (12  cts. 
per  square  yard)  for  the  most  porous  stones." 

606.  "  This  process,  having  been  applied  to  the  new  sculp- 
tures of  the  Lille  Bourse,  to  the  works  of  res- 

n        nr      •  i  i  Examples. 

toration  oi  bt.  Maurice  Chm-ch,  to  the  construc- 
tion of  a  new  church  at  Wazemmes,  to  the  Seclin  Hospital,  in 
some  works  of  military  engineering,  and  in  private  construc- 
tions at  Lille,  has  completely  succeeded." 

607.  "  As  early  as  1841,  MM.  Benvignat,  Marteau,  and  Yerly 
witnessed  the  efficacy  of  this  process.  It  was  also  practised 
elsewhere,  at  Yersailles,  Fontainebleau,  the  Chartres  Cathedral, 
the  Lyons  City  Hall,  the  Louvre,  and  Notre-Dame  at  Paris. 
Yery  able  engineers,  such  as  MM.  Lassus,  Lefuel,  and  Yiolet- 
Leduc,  have  obtained  from  it  the  most  satisfactory  results."* 

608.  "  jStone  Dyeing. — M.  Kulilmann  observing  that  the  sili- 
catization  of  constructions  and  sculptures  gives  rise  to  various 
discolorations  which  showed  the  joints  more  dis-    Mauagement  of 
tinctly,  was  led  to  find  a  remedy  for  this  defect  ^o^^^- 

in  his  process.  By  means  of  the  double  silicate  of  manganese 
and  potash,  he  obtained  a  blackish  solution  applicable  to  cal- 
careous stones  of  too  light  a  color.  By  diluting  in  the  silicious 
solution  some  artificial  sulphate  of  baryta,  those  limestones 


♦Although  proofs,  apparently  the  most  conclusive,  of  the  efficacy  of  the  alkaline 
silicates  as  indurating  agents,  may  be  multiplied,  the  subject  still  appears  to  be 
surrounded  with  practical  difficulties ;  and  the  advocates  of  the  new  theory  meet  at 
every  turn  reports  of  unsatisfactory  results  or  mortifying  failures.  The  "  London 
A-thenseum"  of  August,  1859,  contains  a  statement  that  the  exterior  walls  of  Noire 
Dame^  and  the  Palace  of  the  Louvre  are  in  a  very  unsatisfactory  condition,  that  the 
rains  had  apparently  destroyed  the  preservative  powers  of  the  silicate,  before  the 
surface  had,  by  the  absorption  of  carbonic  acid  gas,  attained  a  degree  of  hardness 
sufficient  to  resist  their  action. — Author. 


316  PRACTICAL  TREATISE  ON  LIMES,  ETC. 

that  are  too  dark  are  lightened  up.  He  found  that  the  porous 
limestones  submitted  to  ebullition  in  solutions  of  metallic  sul- 
phates of  oxides,  insoluble  in  water,  cause  the  fixing,  at  a  certain 
depth,  of  said  oxides  in  intimate  combination  with  the  sulphate 
of  lime.  With  sulphate  of  iron,  he  obtains  a  rusty  color  more 
or  less  dark  ;  with  sulphate  of  copper,  a  magnificent  green  dye ; 
with  sulphate  of  manganese,  brown  hues;  with  a  mixture  of 
the  sulphates  of  iron  and  of  copper,  a  chocolate  color,  &c.  He 
also  observed  that  the  double  sulphates  thus  formed  penetrate 
into  the  stone  and  also  increase  its  hardness." 


THE  END. 


APPENDIX. 


DESCRIPTION  AND  ANALYSIS  OF  THE  COST  OF  SEVERAL 
QUALITIES  OF  CONCRETE  USED  IN  THE  CONSTRUCTION 
OF  THE  FORTIFICATIONS  ON  STATEN  ISLAND,  NEW  YORK 
HARBOR,  DURING  THE  YEARS  1870  AND  1871. 

DESCRIPTIOK  OF  MATERIALS  USED. 

Portland  Cement. — Portland  cements  from  three  localities 
were  used  during  the  two  seasons,  viz.,  from  Stettin,  Germany, 
from  Boulogne  Sur-Mer,  France,  and  from  the  Thames,  near 
London,  England. 

They  were  found  to  differ  very  little  in  quality.  The  tests 
of  strength  made  from  time  to  time  showed  the  Boulogne 
cement  to  be  a  little  superior  to  either  of  the  others,  but  the 
difference  in  this  respect  was  about  compensated  by  its  extra 
cost. 

The  Boulogne  and  the  London  Portland  cements  used  on  the 
Staten  Island  works  through  two  consecutive  seasons,  as  well  as 
several  thousands  of  barrels  received  ia  l^ew  York,  and  tested, 
either  for  private  use,  or  for  officers  of  the  corps  of  Engineers 
located  at  distant  points,  have,  with  one  exception,  been  found 
to  be  fully  up  to  the  standard  exacted  by  the  English  aud  the 
French  Engineers. 

The  use  of  the  Stettin  cement  on  the  fortifications  has  been 


318 


APPENDIX. 


limited  to  one  invoice,  which  was  entirely  satisfactory  as  to 
quality,  hut  fell  short  in  weight  seven  pounds  to  the  cask.  In- 
asmuch as  manufacturers  of  Portland  cement  invariably  sell  by 
weight,  this  difference  is  of  no  moment,  except  to  dealers  and 
consumers  who  purchase  by  the  cask. 

STANDARD  QUALITY  OF  THE  CEMENTS  USED. 

Portland  cement  should  weigh  not  less  than  106  lbs.  to  the 
struck  imperial  bushel,  loosely  measured,  and  should  be  ground 
so  finely  that  at  least  ninety  per  cent,  of  it  will  pass  a  ISTo.  35 
wire  gauze  sieve,  of  47  wires  to  the  lineal  inch  each  way. 

When  mixed  with  fresh  water  into  a  paste  of  the  consistency 
of  stifl'  plasterers*  mortar,  without  sand,  and  pressed  into  a  mould, 
it  should,  at  the  end  of  seven  days,  sustain  a  tensile  strain  of 
500  lbs.  on  a  sectional  area  of  2 J  square  inches,  (IJ  inches  by 
l^  inches)  equal  to  222  lbs.  per  square  inch,  having  been  kept 
six  days  in  water.  This  is  a  combination  of  the  tests  applied 
by  the  English  and  the  French  engineers,  that  is,  it  is  the  lowest 
English  standard  of  weight,  the  highest  of  tensile  strength,  and 
the  ordinary  French  standard  of  fineness. 

Cement  of  this  quality  can  be  made  with  as  much  ease  and 
certainty  as  that  of  a  lower  grade,  while  the  increase  in  the  cost 
of  manufacture,  due  to  the  consumption  of  extra  fuel  and  grind- 
ing power,  is  but  trifling.  As  it  is  not  a  wise  policy  to  pay 
ocean  freight  on  an  imported  cement  of  inferior  quality,  the 
highest  standard  of  excellence  should  be  exacted. 

Lime. — The  lime  was  quarried,  burned,  and  ground  at  Eon- 
dout,  Ulster  Co.,  IT.  Y.  It  is  known  in  the  market  as  Kondout 
ground  lime. 

One  barrel  of  this  lime  (268  lbs.  net)  produces  2f  bbls.  of  fine 
powder  loosely  measured,  when  slacked  with  15  gallons  of  water. 
If  water  be  added  in  suitable  quantities,  the  2|-  bbls.  of  loose 
powder  will  yield  If  bbls.  of  paste  of  the  consistency  of  plasterers' 
mortar. 

This  lime  is  not  pure  white,  but  slightly  drab  in  color,  and 


APPENDIX. 


319 


although  it  does  not  possess  any  perceptible  hydraulic  properties, 
it  is  generally  thought  to  make  a  stronger  mortar  than  the 
white  limes. 

Bosendale  Cement — The  Eosendale  cement  was  from  the 
manufactory  of  the  IS'ewark  and  Eosendale  Company.  Its 
quality  ranges  rather  above  the  average  of  American  cements. 
It  weighs  from  70  to  74  lbs.  to  the  bushel,  loosely  measured,  and 
when  made  into  a  stiff  paste  without  sand,  and  pressed  into  a 
mould,  it  will  attain,  in  seven  days,  having  been  six  days  in 
water,  a  tensile  strength  of  140  to  150  lbs.,  seldom  greater,  on 
a  sectional  area  of  2J  square  inches,  equal  to  62  to  66  lbs.  to  the 
square  inch.  It  is,  like  other  Eosendale  cements,  subject  to  very 
considerable  variations  in  quality  from  time  to  time,  and  often 
falls  greatly  below  this  test. 

Stone. — The  stone  used  in  the  several  kinds  of  concrete  des- 
cribed below,  was  prepared  by  crushing  ordinary  limestone  in  a 
Blake's  stone-breaker.  ' 

The  fragments  were  of  all  sizes  below  a  two-inch  cube,  and 
were  of  various  shapes,  being  generally  quite  angular  and  ir- 
regular in  form. 

This  stone  cost  $2.00  per  ton  of  2,240  lbs.,  delivered  to  the 
wharf  at  the  fort  on  Staten  Island. 

Gravel. — The  gravel  was  the  usual  mixture  of  smooth  gravel 
and  pebbles  from  the  sea-shore,  with  the  sand  screened  out.  It 
varied  from  the  size  of  a  pea  to  that  of  a  hen's  egg,  and  cost 
$1.60  per  ton  of  2,240  lbs.,  delivered  on  the  Government  dock 
at  the  works. 

Both  gravel  and  stone  varied  in  size  from  time  to  time  with 
the  different  cargoes,  sometimes  running  a  little  larger,  and  fre- 
quently much  smaller,  than  the  general  average  given  above, 
requiring  corresponding  changes  in  the  proportions  used  for 
making  concrete.  The  mixture  containing  the  least  measure  of 
voids  was  the  one  constantly  sought,  and  it  was  always  found 
between  the  limits  of  eleven  and  fifteen  volumes  of  stone,  to 
fifteen  of  gravel,  that  is,  fifteen  measures  of  gravel  were  mixe'd 
with  from  eleven  to  fifteen  measures  of  broken  stone. 


320 


APPENDIX. 


The  following  table  gives  the  proportions  of  some  of  the 
mixtures  tried  at  various  times,  with  different  sizes  of  stone 
and  gravel : 

voids  23^ 
voids  24^ 
voids  25^^^ 
voids  26^^ 
voids  27^^ 
voids  30^ 

Mill-made  concrete,  for  all  the  various  uses  to  which  it  is  ap- 
plied, possesses  sufficient  superiority  in  quality  over  that  manipu- 
lated by  hand,  as  to  justify  the  expense  of  suitable  power  and 
machinery,  when  operations  of  considerable  magnitude  are  to  be 
carried  on.  The  more  thorough  manipulation  secured  by  machin- 
ery enables  a  smaller  proportion  of  the  cementing  substance  to 
be  used,  and  effects  a  saving  in  the  cost  of  both  materials  and 
labor. 

Portland  cement  of  good  quality,  containing  no  quick-lime  and 
weighing,  say,  106  lbs.  to  the  struck  bushel  loosely  measured, 
requires  42  to  44  per  cent,  of  its  volume  of  water  to  convert  it 
into  a  paste  of  the  consistency  of  masons'  mortar.  When  quick- 
lime is  present,  which  is  often  the  case  with  cements  when  first 
made,  a  larger  amount  of  water  is  needed.  Portland  cements 
that  have  been  overburnt,  or  those  that  have  become  injured 
from  age  or  exposure,  by  the  absorption  of  moisture  from  the 
atmosphere,  and  the  spontaneous  conversion  into  hydrates,  of  tke 
silicates  and  aluminates  and  any  excess  of  quick-lime  formed  in 
the  kiln,  require  less  water  for  mixing  than  they  otherwise 
would. 


13  measures  stone  ) 
15  "  gravel  ) 
15  measures  stone  ) 
15  "  gravel  j 
11 J  measures  stone  ) 
15  "  gravel  ) 
22  measures  stone  ) 
15  "  gravel  j 
12  measures  stone  ) 
15  "  gravel  f 
27  measures  stone  ) 
15       "      gravel  j 


APPENDIX. 


321 


The  following  tables  show  the  quantities  jf  paste  and  mortar 
of  different  qualities,  some  with  and  some  without  lime,  that  can 
be  made  with  one  barrel  of  cement  as  the  basis : 


Cement  Paste. 

1        Boulogne  Portland  Cement  (France). 

Water. 

1  PaPte  produced. 

1 

a 

8 

1  bbl.  (400  lbs.  nett)  =  1.34  bbls.  loose  powder 
1   "  =^1.40 
1   "                       =  1.33  " 

16  gallons 
16 

m  " 

1.17  bbls. 
L19  " 
1.12  " 

As  an  average,  therefore,  from  the  foregoing  table,  1  bbl.  of 
Boulogne  Portland  cement,  as  packed  for  market,  will  produce 
1.35  bbls.  of  loose  powder,  and  1.16  bbls.  of  paste  of  the  con- 
sistency of  plasterer's  mortar. 

Mortar. 


I  Stettin  Portland  Cement  (Germany). 


bbl.  =  392  lbs.  nett 


Sand. 

Water. 

Mortar  produced. 

1 

2 
3 
4 
5 
5 
6 

14  gallons. 
17*  " 
20 
2.5 

28*  " 

35 

42 

1.16  bbls. 
1.80  " 
2.54 
3.36 
4.00  <' 
4.77  " 
5.40  " 
5.70  " 

Mortar. 


Boulogne  Portland  Cemeut. 

Sand. 

Water. 

Mortar  produced. 

1 

2 
3 
4 
6 
6 
7 

1  bbl.  (400  lbs.  nett) 

1        >(                           It  it 

1        ii                ((        H  (C 
1        11                ((       (I  (t 

1        ((                ((       ((  (( 

1 

2 
3 
4 
5 
6 

16  gal 

21 

23* 

28* 

35* 

43* 

51 

ons. 

1.12  bbls. 
1.38  " 
2.54  " 
3.31  " 
4.19  " 
4.92  " 
5.65  " 

Cement  and  Lime  Paste. 


Boulogne  Portland  Cement. 


1  bbl. 
1  " 


(400  lbs.  nett)  =  1.40  bbls.  loose  powder. 
"   "      "    =  1.35  " 
"   "      "    =  1.35  " 
"   "      "    =  1.31  " 
"   "      "    =  1.38 
"   "      "    =  1.34  " 


Gi-ound  Lime 
slaked  (powder.) 


1.25  bbl 
1.25 
1.25 
1.50 
1.50 
1.50 


Paste 
produced. 

bbT^~ 
85  " 
92  " 
27  " 
34  " 
5  " 


Mortar. 


Boulogne  Port.  Cement. 


Slacked 
Lime 

powder 
loose. 


Water. 


Paste 
produced. 


Additional 
Sand.  Water. 


Mortar 
produced 


1  1  bbl.=  1.31  bbls.  loose  pow. 

2  1"=  1.38  " 

3  1"=  1.34   "  " 

4  1  "  =1.35  " 


1.5 
5 
1.5 
2.62 


bbl. 


32*  galls.!  2.27 
32*  "  2.34 
32*     "  2.15 


30  . 
27* 
33*. 


7.6.-)  bbls. 
7.69  " 
7.54  " 
10.37  " 


322 


APPENDIX. 


MORTAK. 


Rosendale  Cement. 

Sand. 

Water. 

Mortar  produced. 

1 

3 
4 
5 

1  bbl.  (300  lbs.  nett). 
1  " 
1  " 
1  " 
1  " 

1  bbl. 

2  " 
3 

4  " 

15  galls. 
178 
21  " 
25  " 
30 

1.05  bbls. 
1.69  " 
2.50  " 
3.27  " 
4.05  " 

Concrete  Number  1. 

1  Bbl.  Germau  Portland  cement  (393  lbs.)  $3.45  [  ^  a  u^Io  ^^^.^vnfo  r^^vfo,. 
5i  -   damp  sand  loosely  measm-ed,  |.  33  f 

6  "  gravel  and  pebbles  from  seashore  $1.94)=rJ^t„  "^jiwr.  ^nJ^tl 5^.1^1 !! 
Q    a    broken  stone  28  f  shaken    down  contammg 

y        bi olicn  stone,  ^d.Z^  J       p^^.  ^^^^^  ^^-^^^ 

One  batch  of  concrete  composed  as  above,  makes  fifty  cubic 
feet  of  rammed  concrete.  Tliis  is  an  average  of  several  batches. 
This  concrete  is  of  first-rate  quality,  being  compact,  free  from 
voids,  and  strong.  It  is  richer  in  mortar  than  would  be  neces- 
sary for  most  purposes. 

The  cost  of  the  materials  for  one  cubic  yard  of  this  concrete  delivered 
at  the  concrete  bed  ready  for  use,  omitting  the  Custom-house  duty 
on  the  cement,  amounts  to  $4.86 

The  cost  of  mixing,  transporting,  and  ramming  the  concrete,  per  cubic 

yard,  amounts  to  $1.37 

Lumber  and  timber,  and  carpenters'  labor  in  setting  up  same,  $  .32 

Total  cost  of  concrete  per  cubic  yard,  $6.55 
The  cost  of  labor  is  based  upon  the  following  prices  for  a  day's 
work  of  ten  hours:  sub-overseer,  $3.50,  mason  or  carpenter  set- 
ting plank,  $3.80,  and  laborers,  $1.80. 

The  labor  in  constructing  concrete  magazines,  in  consequence 
of  the  extra  work  in  setting  the  planking  at  the  entrance  angles 
and  doors,  and  in  making  and  setting  the  centres,  and  the  con- 
sumption of  extra  lumber,  will  amount  to  about  $1.90  per  cubic 
yard  instead  of  $1.69,  as  given  above. 

Concrete  ISTumber  2. 

1  Bbl.  German  Portland  cement  (393  lbs.)  $3.45  )  ^      ^^^^  ^^^^^.^^^ 
6    "    damp  sand  loosely  measured,        $  .36  ) 

5  "  gravel  and  pebbles  from  seashore,  $1.62  |  Mixed  together  and  shaken 
9    "    broken  stone,  $3.28  f  down,  contains  30^  of  voids. 

One  batch  of  Number  2  makes  50  cubic  feet  of  rammed  concrete. 

The  materials  for  one  cubic  yard  of  concrete  Number  2,  cost,  delivered 

at  the  concrete  bed,  $4.70 

Cost  of  mixing,  transporting,  and  ramming,  per  cubic  yard,  $1.37 

Lumber  and  timber,  and  carpenters'  labor  in  setting  up  same,  $  .32 


Total  cost  of  concrete  per  cubic  yard, 


$6.39 


APPENDIX. 


323 


Concrete  IN'tjmber  3. 

1  Bbl.  Boulogne  Portland  cement  (400  lbs.)  $3.45  ) 

1    "    Slaked  ground  lime  in  powder,         $  .58  >■  =7.  Bbls.  mortar. 

7  "   loosely  measured  damp  sand,  $  .42  ) 

13    "    Gravel  and  pebbles  from  seashore,  $4.20  j*  V^^^^^ 
13    "    Broken  stone  |.  ^4  ^  getber  and  shaken  down, 

Id        tJioken  stone,  74  j  ^.^^^  ^4^  ^^.^^^^ 

One  batch  of  concrete  Number  3  makes  86J  cubic  feet  of 
rammed  concrete. 

Strength  of  the  mortar.  The  mortar  with  which  concrete 
Number  3  is  made,  composed  of  1  bbl.  Portland  cement,  1  bbh 
of  shiked  ground  lime  in  powder,  and  7  bbls.  of  sand,  possesses, 
when  two  months  old,  a  crushing  strength  of  300  lbs.  to  the 
square  inch,  the  test  being  applied  to  5  inch  or  6  inch  cubes. 

Cost  of  concrete  Number  3.  Cost  of  materials  for  one  cubic  yard,  $4.18 
Cost  of  mixing,  transporting,  and  ramming,  per  cubic  yard,  $1.37 
Lumber  and  timber,  and  carpenters'  labor  in  setting  up  same,  $  .32 

Total  cost  of  concrete  per  cubic  yafd,  $5.87 
Concrete  Number  4. 

1  Bbl.  Boulogne  Portland  cement,  (400  lbs.)  $3.45  ]  -7  9  Bbls  concrete  mor- 
\\  "     Slaked  ground  lime  in  powder,       $  .72    "  ^-I^D'S-concrete  moi- 

8  "     loosely  measured  damp  sand,  $  .48  ) 

16  "  Gravel  and  pebbles  from  seashore,  $5.17  " tier  Pnd  shaklrlwn 
16    "     Broken  stone,  $5.82  \  ^^-,,0^2  T 

'  .  ^       )  with  24^  of  voids. 

One  batch  of  concrete  Number  4  makes  105  cubic  feet  of 
rammed  concrete,  of  suitable  quality  for  most  kinds  of  massive 
work.  It  contains  the  greatest  admissible  proportions  of  gravel 
and  broken  stone.  The  quality  of  the  concrete  would  be  im- 
proved by  using  18  barrels  of  gravel  and  14  of  broken  stone, 
instead  of  16  barrels  of  each. 

Strength  of  the  mortar.  The  mortar  of  concrete  Number  4, 
composed  of  1  barrel  of  Portland  cement,  1\  barrels  of  slaked 
ground  lime  in  powder,  and  8  barrels  of  sand,  possesses  a  crush- 
ing strength  of  220  lbs.  to  the  square  inch,  when  two  months 
old,  the  pressure  being  applied  to  5  inch  or  6  inch  cubes. 

Cost  of  concrete  Number  L  Cost  of  materials  for  one  cubic  yard,  $4.02 
Cost  of  mixing,  transporting,  and  ramming,  per  cubic  yard,  $1.37 
Lumber  and  timber,  and  carpenters'  labor  in  setting  up  same,  $  .32 

Total  cost  of  concrete  per  cubic  yard,  $5.71 


324 


APPENDIX. 


Concrete  ^sTumbek  5  (made  with  Eosendale  cement) : 
1  Bbl.  Rosendale  cement  (300  lbs.)       $1.77  ) 

3   "    Damp  loose  sand,  $  .18  >•  =3.27  Bbls.  concrete  mortar. 

5    "     Broken  stone,  $1.82 ) 

This  batch  of  concrete,  as  the  average  of  an  entire  season'? 
work,  has  been  found  to  yield  21.75  cubic  feet,  rammed  in 
position. 

Strength  of  the  mortar.  The  mortar  of  concrete  ISTumber  5, 
composed  of  1  barrel  Rosendale  cement  and  3  barrels  of  sand, 
possesses  a  crushing  strength  of  130  lbs.  per  square  inch  when 
two  months  old,  the  test  being  applied  to  5  inch  or  6  inch  cubes. 

Cost  of  concrete  Number  5.  The  materials  for  one  cubic  yard  cost  $4.67 
Cost  of  mixing,  transporting,  and  ramming,  per  cubic  yard,  $1.37 
Lumber  and  timber,  and  carpenters'  labor  in  setting  up  same,  $  .32 

Total  cost  of  concrete  per  cubic  yard,  $6.36 
Concrete  J^umber  5  is  the  standard  quality  of  Rosendale  cement 
concrete  generally  adopted  upon  government  works.  It  pos- 
sesses sufficient  -strength  in  foundations  and  thick  walls  for  any 
position  in  which  concrete  is  usually  placed.  The  nearest 
approximation  to  it  in  quality  and  strength,  of  any  of  the  Port- 
land cement  concrete  used  at  Fort  Tompkins,  is  concrete  Num- 
ber 6  given  below. 

Concrete  Number  6. 
In  this  concrete  the  proportion  of  mortar  to  the  broken  stone, 
adopted  for  the  Rosendale  cement  concrete  Number  5,  has  been 
carefully  maintained. 

Portland  cement,  1  Bbl.  $3.45] 

Ground  lime,  1  Bbl.  producing  of  lime         1  =  to  10.37  Bbls.  of  concrete 

powder  2f  Bbls.  $1.50  j  mortar. 

Sand,  10  Bbls.,  $  .60  J 

Broken  stone,  16  Bbls.,  $5.82 

One  batch  of  concrete  produces  6 9 J-  cubic  feet,  rammed  in 
position. 

St/rength  of  the  mortar.  The  mortar  of  concrete  Number  6, 
composed  of  1  barrel  Portland  cement,  1  barrel  ground  lime 
(producing  2|  bbls.  slaked  powder),  and  10  bbls.  sand,  possesses 
a  crushing  strength  of  154  lbs.  to  the  square  inch  wlien  two 


APPENDIX. 


325 


months  old,  the  pressure  being  applied  to  5  inch  or  6  inch 
ciubes. 

Cost  of  concrete  Number  6.  Cost  of  materials  for  one  cubic  yard,  $4.41 
Cost  of  mixiiif^,  transporting,  and  ramming;,  per  cubic  yard,  $1.37 
Lumber  and  timber,  and  carpenters'  labor  in  setting  up  same,  $  .33 

Total  cost  of  concrete  per  cubic  yard,  $6.10 

This  concrete  therefore  possesses  two  advantages  over  con- 
crete I^umber  5,  viz,  :  the  mortar,  although  used  in  the  same 
proportions  to  the  broken  stone  as  in  Number  5,  costs  nearly 
11  per  cent,  less,  and  is  more  than  18  per  cent,  stronger. 

Hand-made  concrete.  All  the  several  kinds  of  concrete 
described  above  were  made  by  hand,  after  the  manner  indicated 
in  paragraphs  366  to  376. 

When  lime  was  used,  the  slaked  lime  powder  and  the  dry 
cement  were  rudely  mixed  together  on  the  mortar-bed  before 
the  sand  and  water  were  added. 

Mill-made  concrete.  The  mill  used  for  mixing  concrete  is  a 
cubical  wooden  box  measuring  four  feet  on  each  edge  in  the  in- 
side. It  is  provided  on  one  face  with  a  trap-door  about  two 
feet  square,  close  to  one  of  the  angles,  and  is  mounted  on  an 
iron  axle,  passing  through  opposite  diagonal  corners.  An  ar- 
chimedean  screw  mortar-mill,  for  mixing  the  concrete  mortar,  is 
used  in  connection  with  the  box,  and  both  are  driven  by  a 
small  engine  of  about  six-horse  power.  Eight  revolutions  of  the 
box,  made  in  less  than  one  minute,  are  found  to  be  quite  suf- 
ficient to  produce  the  most  thorough  incorporation  of  the  mortar 
with  tlie  broken  stone  and  gravel.  Every  piece  of  stone,  and 
every  pebble  and  gravel,  become  completely  coated  over  with 
mortar. 

In  making  the  mortar,  the  cement,  lime,  and  sand  are  first 
rudely  mixed  together  with  shovels  on  the  mortar-bed,  and  are 
then  passed  through  the  mill  once;  one  measure  of  the  dry 
mixture  (about  a  cubic  foot),  alternating  with  one  small  measure 
of  water. 

The  precise  amount  of  water  necessary  is  determined  by  trial, 
and  will  vary  from  time  to  time  with  the  more  or  less  moist 
condition  of  the  sand. 


326 


APPENDIX. 


Four  men  with  barrows  are  employed  in  conveying  the  con- 
crete materials  (the  mortar,  broken  stone,  and  gravel)  into  the 
concrete  box,  one  barrow  full  of  the  mortar  (2  cubic  feet)  alter- 
nating with  three  heaped  up  barrows  full  of  the  coarser  ingre- 
dients (7  cubic  feet).  The  materials  are  dumped  into  the  box 
from  a  staging,  erected  on  the  level  of  the  trap-door  when  at 
its  highest  point. 

One  charge  of  the  box  contains  : 

4  barrows  of  mortar  (8  cubic  feet). 

6  heaped  up  barrows  of  broken  stone  (14  cubic  feet). 

6      "      "      "  gravel  (14   "      '  ). 

After  mixing,  the  trap -door  is  opened  and  the  contents  de- 
posited on  the  platform  below,  by  two  or  three  revolutions  of 
the  box.  The  concrete  box  produces  such  a  thorough  and  com- 
plete trituration  of  its  contents,  that  it  is  not  necessary  that  the 
mortar  should  be  mixed  beforehand.  The  mortar-mill,  as  an 
auxiliary,  may  therefore  be  dispensed  with.  The  ingredients  of 
the  mortar  (the  cement,  lime,  sand,  and  water),  after  being  pro- 
perly proportioned  by  measure  and  rudely  mixed  together  with 
shovels,  require  no  further  preparation,  but  may  at  once  be 
added  to  the  coarse  materials  in  the  box. 

The  method  of  charging  the  box  by  barrows,  practised  at  the 
Staten  Island  works,  is  not  considered  the  most  economical  that 
can  be  devised. 

A  crane  or  derrick  worked  by  the  same  engine  that  turns  the 
box,  and  having  a  sweep  of  sufficient  length  to  reach  the  mor- 
tar-bed, and  the  piles  of  broken  stone  and  gravel,  would  doubt- 
less be  an  improvement. 

A  concrete  box  employed  by  General  Duane  in  Portland 
Harbor,  Maine,  is  operated  in  this  way. 

One  box  of  the  capacity  above  described  (4'  x  4.'  x  4'  on  the 
inside)  will  mix  from  95  to  100  cubic  yards  of  concrete  in  one 
day  of  ten  hours,  and  will  do  the  work  very  mucL  better  than 
it  can  be  done  by  hand,  and  at  a  saving  of  from  15  to  20  per 
cent,  in  the  cost  of  labor. 


INDEX. 


Paragraph. 

Absence  of  upper  layers  of  Rosendale 

cements   40 

Absorption  of  carbonic  acid  by  limes, 

98,  831,  578 
Abundance  of  common  limestones  in  the 

U.  S   1 

Abuse  in  burnino-  limestones   235 

"    in  slaking  lime  by  drowninsf.  320 

Activity,  hydraulic   121,  122,  123 

Adhesion  of  cement  mortars  to  bricks 

and  fine-cut  {granite   543-545 

Adhesion  of  mortars   32,  531-535 

"       of  cement  through  muslin.  536-542 

Advantages  of  concrete   447-448 

"        of  slow-setting  cements.  ...  93 

Aggregates,  meaning  of  term   311 

"  strength  of.   312 

Air,  hydrate  of  lime  in   331-338 

"   cement  deteriorates  in   298 

lime  hardens  in   103 

"   disintearrati on  of  mortars  in   430-438 

Air-slaked  limes,  Totten  on   338 

Air-slaked  hydraulic  lime  308 

Akron  cement  contains  alkalies   591 

cement  manufactory  at   84 

"     cement,  strength  of   . .  557 

Algiers,  concretes  at  mole  of. . ..  154,  15G,  500 

Alkalies  in  American  cements   591 

Alkaline  salts  in  hyd.  limestones   4,  Itt 

"      silicates  acting  on  chalk       141,  147 

"  "  "    sulphate  of 

lime   148 

Alkaline  silicates  in  mortars 

142,  143,  145,  551-553 

Alluvial  clay  for  artificial  cement   129 

Alumina  in  hydraulic  limestone   4 

how  detected   190,207-209 

"       re-action  of  in  kiln   .585-587 

American  cements,  alkalies  in    591 

"  "       strength  of.  520 

"       limes,   experiments  in  slak- 
ing  327-330 

Analysis  of  Akron  limestone   226 

"      "  Argillo-magnesian  lime- 
stones of  New  York,  New  Jersey, 

and  Virginia   16,  22(5 

Analysis  of  Vicat's  artificial  Portland 

cement   131 

Analysis  of  Cumberland  limestone,  Md..  226 

"  Englii^h  cement  stones   2-26 

"      "  James  River  cement   226 

"  laitance   474 

"      "  Lockport  cement,  Niagara 

Co..  N.  Y   226 

Ammonia,  molvbdate  of   196,  201,  202 

oxalate  of,   192,  193,  213 

pure  water  of, 

190-192,  202,  203,  207,  208,  210 


Paragraph. 

Anaylsis  of  Maine  cement   23 

"•      "  Massachusetts  cement   22 

"      "  Mississippi  cement   25 

"  "  Point-aux-Roches  cement. . .  226 
"      "  Boulogne  Portland  cement. .  95 

"      "  Pozzuolana   226 

"      "  Round  Top  cement,  Md   226 

"      "  Sandusky,  O.,  cement   226 

"      "  Shepherclstown,  Va.,  cement.  2-26 

"  Theil  limestone   2->6 

"  Trass   226 

"      "  Ulster  Co.  cement   226 

"      "  Utica,  111.,  cement   226 

"      "  Vassy  cement,  France  226 

"      "  white  marble   100 

Ancients  used  Pozzuolana   Ml 

Appalachian  chain,  limestone  in   3,  12 

Apparatus  for  trying  cements   173 

Arenes   102,  111,  116-118 

"     are  hydraulic   116 

"     hydraulic  activity  of  increased  by 

burning   117 

Aro-illaceous  limestones  ot  U.  S   5 

Argillo-calcareous  deposits  of  Portland 

cements   87.  88,  129 

Argillo-magnesian  limestones  in  U.S. 5. 12,  110 
"  "  ill  New 

York,  New  Jersey,  and  Virginia. . .  13-16 

Artificial  cements   125-145 

"       hardening  by  Kuhlmann's  and 

Ransome's  processes   600-607 

Artificial  hydraulic  lime  of  St.  Leger. . .  133 
"  "         Chatony.  ...  134 

"      means   of    hardening  stone, 

brick,  mortar,  etc   593-607 

"      Portland  cement  88,  12S-132 

"      Pozzuolana-mortars,  in  the  sea  150 
Pozzuolana's..l24,  135-139,  150,  151 

Balcony  Falls,  Va.,  cements  at        15,  79,  124 

Barnegat  limestone   10 

Baryta,  nitrate  of   188 

Basaltic  sands   102,  111,  119 

Bastard  stucco   408.  412 

Belgrand  &  Michelot's  experiments  ()f.523.  524 
Beton  or  concrete   161,  4')9-.507 

"     definition  of,  &c    439-440 

Bi-chloride  of  platinum   194-195 

Bird's-eye  limestones   7,  1 1 

Bituminous  matter   197 

Black  river  group  of  limestones          7,  11,  15 

Blocks  of  concrete  494,  496,  500,  505 

Blue  lias  limestones  44] 

Blue  limestone  of  Kittatinny  Valley   11 

"         "      and  marls  of  the  West   11 

Blue  ridge  Quarry,  Va   79 

Bolting  cement   291 

Boulogne  pebbles  or  Septaria. . .  .  ...  87,  51^ 


328 


INDEX. 


Parag:raph. 

Boulogne  Portland  cement   87-95 

Boulogne  Roman  cement   92 

Box  lor  lowering  concrete  in  water. ,  466-468 

Brard's  frost  test   434 

"Breaking  the  set''  destroys  hydraulic 

energy    144 

Breaking  weight  of  cement  and  lime 

without  eand   547-550 

"  "      of  pure  cement   520,529 

"  "      of  Portland  and  Roman 

cements          526,  528,  530 

"  "      of  pure  and  mixed 

American  and  European  cements.555,  557 
Breaking  weight  of  Trass  and  Pozzuolana 

mortars   559 

Brick  masonry,  mortar  for  380 

hardened  artificially. .  593-607 

Brown  coat   414 

Bruce,  N.,  cement  works  of   65 

Burning  cement  atones,  abuse  in   235 

"      capricious  variations  while.  268-287 

"      care  to  be  exercised  in   286 

defects  of  method  ot  232 

kilns  for   237-253 

"      necessity  of  care  in   258 

observations  on...  233-236,  263-2,s7 
Burning  hydraulic  limestone.  582,  584-587,  590 
"      where  alumina  is  present. . .  585-587 
silicious  limestones  584 

Calcareous  beds  of  calciferons  group   11 

"        clay  for  Boulogne '  Portland 

cement   87-91 

"       beds  on  Potsdam  sandstone. .  6 

minerals,  purest   100 

"        mortar,  definition  of   309 

"  uses  of   310 

"       sand,  mortars  containing  only  579 

sandrock   7,8,9,11 

Calciferons  group  or  formation  7-11 

Calcination  of  Portland  cement  89 

conduct  of  cem'ts  during.268-287 

"         of  dissimilar  stones   171 

"         improves  Pozzuolanas, 

135,  136,  264 

"         of  St.  Leger  hy.  lime   133 

"         of  artificial  cement         127,  130 

Calcium  the  base  of  lime   96 

Capacity  of  Cumberland  cement  works  77 
"       "   James  River      "          "  79 
"       "   Kensington  (Conn.)  cement 
works   83 

Capacity  of  Louisville  (Ky.)  cement  works'  82 
Round  Top  "       "         "  75 
"  Sandusky  (O.)       "  81 
"      "  Shepherdstown  (Ya.)  cement 
works   72 

Capacity  of  Utica  (111.)  cement  works. . .  80 
"       '•  Delafield  &  Baxter  cement 
works   63 

Capacity  of  Hudson  River  cement  works  67 

"       "  Lawrence  Cement  Co   60 

"       "  Lawrenceville  Cement  Man- 
ufacturing Co    69 

Capacity  of  works  of  Maguire,  Crane  & 
Co   68 

Capacity  of  works  of  Marting&Clearwater  66 
"      •'     "  the  Newark  Lime  & 
Cement  Manufacturing  Co   58 

Capacity  of  works  of  Newark  and  Rosen- 
dale  Co   61 

Capacity  of  works  of  Ogden  Rosendale  Co.  64 
"     "     "  Rosendale  Cem't  Co.  62 
"      "     "     "  Rosendale  &  Kiug- 
eton  Cement  Co  ,.   70 


Paragraph. 

Carbonate  of  lime   96 

"       "   '*   in  hydraulic  limestones  4 

"        "   "   on  sea-walls   160 

"       "  magnesia  in  hydraulic  lime- 
stones  4 

Carbonate  of  magnesia  on  sea-walls   160 

Carbonic  acid  absorbed  by  limes, 

98,  103,  331,  578 

Caustic  lime  in  cement  mortar  44,  49, 123 

Cements  at  certain  stages  of  burning   269 

"      American,  trials  of   520 

"      artificial  hydraulic   125-145 

"      of  Black  River  limestone   15 

color  of  292 

Cement  deposits,  heterogeneous   167 

"  "        in  Ulster  Co     44 

"      for  drain-pipes   463 

"     and  hydraulic  limes  102-109 

"      action  of,  in  sea-water   158 

Cementing  substance,  theoretical  mini- 
mum of   314 

Cements  will  not  slake   109 

Cement  and  lime  mortars  compared   382 

Cement  manufactory  at  Akron,  N.  Y   84 

Cement  works  at  Balcony  Falls,  Va,  

15,  79,  124,  226,  264,  295 

"         "       cost  of  running   82 

at  Lockport,  N.  Y   84 

"  Chittenango,  N.  Y... .  84 

"         "       "  Fayetteville,     "    84 

"  Manlius,  N.  Y    84 

"         "       "•  Kensington,  Conn.  ..  24 

in  the  West   24 

"  on  the  Potomac   15 

Cement  mortars,  the  efi'ect  of  lime  in,  549,  550 
"  "        harden  simultaneously 

throughout  36.  37 

"  "        why  lime  is  added  to..  546 

"  precautions  in  testing.28-29 

"  "        proportion  of  lime  in,  381 

Cements,  the  basis  of  concrete  mortar  in 

the  U.  S  445 

Cement  paste,  through  muslin   537-542 

Cements,  precautions  in  testing   122 

"       with  excess  of  water   509 

"       preservation  of    2S)8 

"       (Rosendale)   contain  alkaline 

salts   16 

Cement  stone,  analysis  of  Eno-lish   226 

"         "    difficulty  in  selecting   170 

"  "  prominent  features  of. . .  46-95 
"  "  general  features  of  layers  ol,  168 
"         "    hydraulicity  of  underburnt  177 

"         "    in  Mississippi   25 

"  inertness  of  overburnt   177 

"         "    kilns  for  burning  

228-232,  237-241 
"         "    observations  on  burning  of, 

233-23r. 

"         "    preliminary  trials  of. ..  172-182 

"     stucco,  hydraulic   423-429 

Cements,  some  good  at  all  stages  of  burn- 
ing  268 

Cements,  with  silica  in  excess    .592 

Chalk  and  clay,  for  artificial  cement.  128.  129 
Changeable  character  of  cement  stones. .  40 
Character  of  limestones.  ..  163-165,183-186 
Characteristics  of  intermediate  limes  ...  110 

"  "  pure  limes   96 

Chatoney  and  Rivot,  on  hydraulic  mate. 

rials   151,152 

Chaux  limites  of  Vicat   43,  110 

Chazy  group  of  limestones   7,  11 

Cherbourg  breakwater   504 

Chittenango,  N.  Y.,  cement  works  at. . . .  84 


INDEX. 


329 


Paragraph. 

Classification  of  hydraulic  limes         107,  108 

"  "  limes  for  mortar   102 

Coarse  Ptuff  for  plastering,  394-396,403, 404, 409 

Cofferdam,  by  Maj.  Hunt   473 

Cohesive  strength  of  cement  through 

muslin     539,  540 

Color  of  cement   57,292 

"     "  stucco,  management  of   429 

Combinations  of  good  and  bad  limestones 

for  cements  . .    44 

Commercial  limestone   101 

Common  limes   102-104 

"         "   paste,  under  water   103 

"         "   concrete  containing. . .  490-492 

"      mortars,  for  outside  stucco   419 

Comparison  of  cement  and  lime  mortars  382 
Composition  of  concrete  at  Loveli's  Isl- 
and   488,  489 

Composition  of  mortar   379-380 

"         "  pointing  mortar   .385 

Compound  limestones   2 

Concrete  or  beton   161,  439-507 

"         definition  of  439 

"      blocks  500-505,  515 

"•      for  the  Cherbourg  breakwater  504 

"      coarse  ingredients  of   476-507 

"      use  of  in  the  U.  S   506 

"      of  Forts  Richmond  and  Tomp- 
kins 4!S3,  484,  486,  4S7 

"      injected  under  water   494-497 

"      general  practice  in  making. 445,  446 

"      ramming   455 

"      jetties  at  Marseilles   502 

"      laid  under  water    464^75 

"      English  mode  of  making   444 

"      made  by  machinery  451-453 

"      materials  for   478 

"      may  contain  common  lime.  .490-492 

"      for  Boston  fortifications  449,  450 

"      for  mole  at  Algiers   500 

"        "  graving  dock  at  Toulon.  ...  501 

"      not  rammed  under  water  464-475 

"      proportion  of  matrix  in    440 

"      of  quicklime  441-444 

"      for  roofing  arches   493 

"      in  single  mass  469 

"      cart  for  conveying   456 

"      founding  with   470 

"      advantages  of  447,448 

"      hollow  walls,  devices  for  con- 
structing 457-462 

Concrete,  walls  revetted  with  stone  ..471-473 

"      wheelbarrows  for  conveying   454 

Coral  sand  as  pozzuolanas   136 

Cost  of  concrete  at  Lovell's  Island  488^89 

"       "      at  Fort  Tompkins. .  486,  487 

"    "  plastering   418 

"   "  roofing  concrete  at  Ft.  Warren..  493 

"•   "  manufacturing  cement   82 

"  various  kinds  of  masonry   507 

Cracker  for  grinding  cement   288 

Cretac(!Ous  formation  for  Portland  cement  87 
Crotou-bricks,  adhesion  of  mortars  to.  531-543 

Crucible  tests  of  cement  stones  46,  173-182 

Culmann  on  slaking   325 

Cumberland  cement,  strength  of   557 

"  "      works,  Md.,  77,  78 

"         stone,  analysis  of   226 

Curves  of  energy  of  cements   263-268 

"      "  strength  of  cements  279-285 

Darcel  on  Roman  and  Portland  cement, 

522-524 

Decay,  hardest  stone  liable  to    594 

Device  for  compressing  green  mortars.. .  33 


Devices  for  laying  stone  under  water   53R 

constructing  walls  of  concrete, 

457^62 

Delafield  &  Baxter's  cement,  strength  of,  557 
"  "        works..  63,  124 

Delesse  on  Boulogne  Portland  cement.  .87-95 

Demarle  &  Co.,  Boulogne,  France   87 

DestructibiUty  of  stones,  causes  of   595 

Deteriorated  cements    301 

"•  "       strength  of  James 

River   306 

Deterioration  of  cement  and  lime  in  air, 

298-307 

Difference  in  burning  for  artificial  cement  131 

Dissimilar  stones,  burning  of   171 

Distemper   413 

Dividing  limes  of  Vicat   43,  143,  180 

Dolomitic  earths  as  pozzuolanas   138 

Dover  &  Alderney  Breakwaters  505 

Drain-pipes,  cement  for   463 

Draw  kilns  and  flame  kilns, .  .241-243,  249-256 

Drowning,  slaking  lime  by   319-322 

Totten's  experiments  on   338 

Dunlop's  Creek,  Va.,  cement  from   15 

Dupont's  mill,  for  grinding  cement   88 

Durability  of  stone  596-607 

Eaton,  transition  sandrock  of   10 

Efilorescences,  mural  561-577 

Energy,  curves  of  hydraulic  264-266 

"     hydraulic  121,123 

English  cement,  analysis  of   226 

European  limes  and  pozzuolanas,  in  sea- 
water  150-161 

Europe,  pozzuolanas  found  in    112 

Examination  of  limestones   166-227 

Excess  of  caustic  lime,  in  mortar  44-49 

Experiments  on  limes  and  pozzuolanasl50-161 

Experiments  in  slaking  limes  327-330 

"           by  General  Tot- 
ten    329,  338-344 

Experiments  based  on  change  of  tempera- 
ture  124 

Exterior  plastering  or  stucco  419^9 

Fabrication  of  mortars  342-383 

Fat  limes      102,  103 

Fayetteville,  N.Y.,  cement  works  at   84 

Feburier,  experiments  of   157 

Fertilizer,  poor  lime  as   105 

Fine  stuff  for  plastering  394,  397-399 

Finishing  coat  398,  399,  408-413,  417 

Flame  kiln  241-243 

Floated  coat  404 

Formation  I.  of  Rogers'  classification —  6 
II.  "         "         7,  11,  12 

VL  "         "  38 

Formula  for  rupture  497,  527,  554 

Forge  scales   135 

Fort  Adams,  efflorescences  at  565,  566 

"         experiments  by  General  Tot- 
ten  at  1-21,  499 

Fort  Carroll,  laying  concrete  at  464,  465 

Forts  Richmond  and  Tompkins,  concrete 

for  483-487 

Fort  Taylor,  mortar  mill  used  at    128 

"   Warren,  cost  of  concrete  at   493 

Fossiliferous  limestone   11 

France,  arenes  found  in   116 

"     artificial  cements  in   125 

"     pozzuolanas  found  in   112 

Fresh  water  for  slaking   337 

Frigo rifle  mixtures   433 

Frost,  its  eflect  on  mortars  430-434 

Fuchs  on  Alkaline  sUicates   146 


330 


INDEX. 


Paragraph. 

Fuel  for  burning  cement   230,  254 

Gauge  stuff   399 

General  feature  of  cement  deposits   168 

Geographical  localities  of  argillo-magne- 
sian  limestones  of  New  York,  New 

Jersey,  and  Virginia  13,  14,  15 

Glenn's  Falls  lime   330 

Gneiss-sand,  as  pozzuolana   139 

Goveniors  Island,  concrete  blocks  at   515 

Granites  Ill,  119 

Grauwacke  102,  111,  119 

Grinding  cement  288-291 

Growth,  in  slaking  process   319 

Guadaloupe,  pozzuolana  of   112 

Hand-floating  403,  405-407,  411,  413 

Hand-made  mortar  359,  365-378 

Hardening  of  stone,  etc.,  artificially  .  .593-607 

Hardening  of  cements  under  water   107 

Hardening    under  water,  classification 

based  on   102 

Hard  finish  399,  408,  413,  414 

Hardness  of  arnees-mortar   116 

"         cement  mortars  510-515 

"         mortars,  method  of  testing. .  31 

Harwich  Roman  cement   86 

Helderberg  division  of  hyd.  limestones. . .  18 

Heterogeneity  of  cement  deposits   167 

High  Falls  cement,  trials  with   529 

Hoffman  brand  of  cement ...  .60,  302,  303,  557 

Holland,  trass  found  in.   113,  114 

Hydrate  of  fat  lime  in  the  air  331-338 

"      "  lime  as  a  chemical  compound  96 

"      "  magnesia   590 

Hydraulic  activity  121,  122,  123,  124,  276 

"       cements  in  sea-water   158 

"       cement  stucco  423-429 

"       cements  require  no  sand   109 

"       cements,  from  Onondaga  Salt 

group   18 

"       cements,  clast^iflcation  of. . .  102-109 

"        energy,  how  destroyed   144 

"        induration,  theory  of   582-592 

Umes  102,  107,  108,  307,  308 

"  "   slake  with  difficulty   322 

"  limestones,  examination  of,  166-308 
"  "         eftects  of  burning, 

582,  584-587,  590 
'*       limestones,  qualitative  exami- 
nation of  183-197 

"       limestones,    quantitative  ex- 
amination of  198-227 

Hydraulicity  of  arenes,  theory  of  116,  117 

"        index  of,  in  Theil  Lime   156 

"         maximum  and  minimum  of, 

263-285 

"        cause  of   182 

"  of  underburnt  cement  stones  177 
Hydro-chloric  Acid,  in  analyses, 

189,  190,  200,  202,  206,  208,  210,  214,  216 
Hydro-chloric  Acid,  pozzuolanas  soluble 

in   112 

Hydrogen,  sulphite  of,  its  use   195 

Hydro-silicate  in  artificial  cement   140 

Illinois,  limestones  in   3 

Immersion,  slaking  by   323 

Impact,  hardness  of  mortars  by   31 

Impurities  in  limestones  101-109 

Increase  of  strength  of  mortars  554-558 

"      of  volume  in  slaking  lime, 

96,  103,  105,  107 

Index  of  hydraulicity   156 

Indiana,  deposits  of  limestones  in   3 


Paragrapli. 

Indurating  mixtures  598 

Induration  by  absorption  of  carbonic  acid  331 

"        in  the  air  ,   103 

"        artificial  597-607 

"        of  hydraulic  limes   332 

"        hydraulic,  theory  of   582-592 

"        of  mortars  of  fat  limes...  578-581 

Inertia,  instant  of   177-179 

Inertness  of  overburnt  cement    177 

Inferior  cement  stone  used   43 

Ingredients  of  artificial  Portland  cement.88,182 

"        "  concrete   476-507 

"        "  hydraulic  limestones  4,  582 

"        "  natural  pozzuolanas   Ill 

"  St.  Leger  hydraulic  lime. . .  133 

Interior  plastering   389^18 

Intermediate  limes   269 

"  "•   improved  by  age   300 

"  "   unfit  for  use, 

47-49,  52,  53,  143, 180 
"  in  the  United  States. 109, 110 

"  "   when  used  under  water, 

110,  143 

Iron,  oxide  of,  how  detected,  &c., 

191,  207,  294-296 

Isle  of  Bourbon,  cements  of   295 

Italy,  pozzuolanas  found  in   112 

James  River  cement  mortars,  strength  of, 

520,  557 

"      "        "  works, 

79,  124,  226,  2.59,  264,  268,  303,  306 

Kensington  cement  works,  Conn   83 

Kentucky,  limestone  in  •  •  •   3 

Kimmeridge  clay,  England   86,  87 

Kilns  for  burning  cement  228-282,  237-241 

"  common  lime  24.5-256 

"     intermittent  244-248 

"     perpetual  231,237-241,249 

Kiln,  starting  the   231 

Kingston  and  Rosendale  cement  mortar,,  5.57 
Kuhlmann  on  alkaline  silicates..  146,  149,  551 

"         "  efllorescences    5t)8 

"       process  of  silicatization. .  600-607 

"       process  of  stone  dyeing   608 

Kuhlmann's  report   16 

Laitance   468,  474  ,  475 

Lathing,  common  faults  in   404 

Lawrence  cement   62,  5.57 

Cement  Co   60,  61 

Lawrenceville  Manufacturing  Co.   69 

Layers  of  cement,  general  feature,  of..  168 

"  Rosendale  cements   39 

Laying   401,  403-405 

coat  and  set   404 

"     concrete  under  water   464-475 

"     stone  under  water,  device  for,  536-542 

Light  Rosendale  cement   57 

Liquor  of  flints   60^ 

Lime  in  cement  mortars    5-n 

"   and  arenes   ...  lit 

Lime,  alkaline  salts  in   16 

"     concrete  containing  coninion490-492-496 

"     for  stucco   4-JO 

"     mortars  with  pozzuolana          588,  589 

"         "      with  trass   558,  55!> 

"     quantity  of,  how  determined..  192,  213 

"     in  cement  mortars   549,  550 

"     mortar  over  arches   498 

"     added  to  trass   113 

"     preservation  of   339-341 

"     pure,  how  tested    99 

"     method  of  slaking   317-383 


INDEX. 


331 


Paragraph. 

uime,  the  characteristics  of.   96 

"     added  to  cement  mortar   381 

"     added  to  pozzuolana   112 

"     for  vvhitewashing   321 

Limes  as  sources  of  mortar   102 

common      102-101 

Lime,  kihis  for  bnrning  •   245-256 

hydraulic  slakes  with  difficulty —  322 

"     hydraulic   102,  107,  108 

induration  of   331,  578 

"     intermediate   109,  110 

"     poor  or  meagre   102,105,106 

Limestone  and  chiuk, action  of  silicate  on.  147 

Limestones,  argillo-magnesian   12,  16 

"  in  New  York,  New  Jersey, 

Virginia,  and  Penns^ylvania   13-15 

Limestones  containing  alumina   585-5S7 

'•       diversified  character  of. .  163-165 

"       examination  of   106-308 

"       hydraulic,  effects  of  burning, 

58i,  584-587,  590 
"  "        mineral  character  of  183 

analyf^isof   183-227 

"silicious,  products  of  burning   584 

Limestones  underburnt   136 

Lockport,  cement  works  at...  .84,  226,  262-265 

Louisville  cement  works   82,  124 

Lovell's  Island  concrete,  Boston        488,  489 

Machine  for  breaking  stone    479-482 

"      "  making  concrete   451-453 

"      "       "      drain  pipes    463 

Magnesia  a  protection  of  sea  walls   161 

"      deposit   18,  19 

"      how  detected  in  limestones,  191,  212 

hydrates  of   590 

limestones  of  the  West   10 

Maguire,  Crane  &  Co's  cement  worlis   68 

Malaguti  &  Durocher  on  mortars         294,  296 

Manganese,  how  detected  in  limestones, 

191,  212 

"         oxide  of   293 

Manlius,  cement  works  at   84 

Manufacturers  neglect  assorting  the  stone  42 

Marsseilles,  concrete  for  jetties  at  502 

Martins  &  Clearwater's  cement  works. . .  66 

Martinique,  pozzuolanas  found  in   112 

Masonry,  cost  of  various  kinds  of   507 

"      volumes  of  mortar  in   507 

Massachusetts,  limestone  in.   22,23 

Maximum  and  minimum  hydraulicity  269 

Meagre  limes    102 

Memoir  by  Chatoney  &  Rivot,151, 152,  508-519 

Method  of  burning  (ements   232 

Method  of  slaking  hme  317.  359-364,  383 

"         testing  strength  of  mortars, 

27,  32,  531-535 

Mills  for  grinding  clay   88 

"     "  chalk.   128-132 

Minard's  opinion  of  tests  for  mortar   438 

Mineral  character  of  limestones   183-186 

Mississippi,  limestones  in.   25 

Mixing  stands  for  mortars   315 

Modifications  of   ordinary   method  of 

slaking  lime.   360-364 

Moisture  absorbed  by  lime   98 

Molybdate  of  ammonia   196,  201,  202 

Mortar,  action  of  magnesia  on  setting  of  590 

ofarenes,  with  rich  lime   116 

"     artificial  hydraulic   125 

"     of  artificial  pozzuolanas  in  sea 

water   ..  150 

Mortar  box  and  cart   383 

"     cement  hardens  simultaneously 
throughout   36,37 


Paragrrapli 

Mortar  of  common  lime,  where  employed  104 

"  "     setting  of  .581 

"    containing  calcareous  sand  only. .  579 

"    cost  of  making   356-358 

"    definition  of  the  setting  of   120 

"    disintegration  of   430-438 

"    eff"ect  of  frost  on   430-434 

"    eftect  of  sea  water  on   435-438 

"    fabrication  of   342-383 

"  of  fat  lime,  induration  of  . . .  578-581 
"    frigorific  mixtures  for  testing. . .  433 

"    of  intermediate  lime   110 

"    made  of  lime  and  trass,  or  lime 

and  pozzuolanas   558-560,  5S8,  589 

Mortar  making  by  hand   359,  365-378 

mill   345,  546,  350-358 

"    mill  at  Ft.  Taylor   350.  351 

"     mill  of  M.  Greyveldinger. . . .  352-358 

"    mill  for  grinding  chalk   132 

"    mill  for  grinding  Portland  ce- 
ment   129 

"    of  the  mole  of  Algiers   154-156 

"■    a  mechanical  mixture   508 

"    pointing   384-388 

of  Portland  cement,  its  superi- 
ority  517-519 

"    proportion  of  ingredients  for,  344,  379 

"    for  various  kinds  of  masonry   507 

"    for  stone  and  brick  mas^onry   380 

Mortars,  strength  of  certain  1,55 

Mortar,  technical  signification  of  term..  31! 

"     used  for  plastering   394-400 

Mud,  argillaceous,  for  Portland  cement. .  129 

Mural  efflorescences   561-577 

Muslin,   its  use  in  laying  stone  under 
water   536-542 

Natural  cement  of  Boulogne   87-95 

Needle  test  of  mortars   35,  36 

"      "  for  mortars  as  to  hardness, 

31,  528,  547 

Newark  Lime  and  Cement  Co   58 

Newark  &  Rosendale  Co ... .          61,  124,  243 

"  cement,  strength 

of   545,  557 

Newburgh  limestone   10 

New  Jersey  limestone   3,  14 

New  York  limestone   3,  13 

Niagara  group  of  Ontario  division  ...  17,  20 

Nitrate  of  baryta   188 

Nitric  acid   196,  200 


Obernai  and  Metz  hydraulic  lime   307 

Ochrous  earth    102,  111 

"      sand   116 

Ogden  Rosendale  Cement  Co   64 

"  "       strength  of .  ,.  555 

Ohio,  limestone  in   3 

Old  method  of  making  artificial  cemen'* ,  132 

One  coat  work   403 

Onondaga  Salt  Group   18,  20 

Oolitic  limestone   lu 

Overburut  cement  stones   177 

Oxalic  acid  to  test  lime   99^ 

Oxide  of  manganese  in  cement   293 

"  of  iron,  how  detected,  191,207,  210,  211 
"    of  iron,  an  ingredient  of  hydraulic 

limestones   4 

Oyster  beds,  artificial   155 

Oyster  shells  used  in  concrete   476 

Pacific  coast,  no  cement  on   26 

Parker's  Roman  cement   292,  294 

Paste  of  lime  under  water   103 

Pennsylvania,  beds  of  limestone  in   i 


332 


INDEX. 


Paragraph. 

Percentasfe  of  day  in  Boulogne  cement. .  87 
"       of  impurities  in  cements  and 

limes   103,  105,  107,  109 

Perpetual  kiln   231,  244 

patent  kiln   237-211 

Petzholdt's  experiments  with  old  mor- 
tars   578,  57f» 

Phenomena  developed  in  slaking  poor 

limes  96,  101,  103,  107 

Phosphoric  acid  in  limestones  1%,  200-206 

Physical  appearance  of  raw  stone  no  cri- 
terion of  its  properties   182 

Pise-work,  boxing  for   460 

Plaster  of  Paris   398,399 

Plasterer's    nomenclature  and  tools, 

390-392,401 

Plastering,  cost  of  418 

"        exterior  and  interior, 

389-392,  419-429 

Plastering,  mortars  used  for   394-400 

Platinum,  bi-chloride  of  194,  195 

Pointing  mortar   384-388 

Polishing   411 

Poor  limes   ...  102,105,106 

Porous  limestones  with  alkaline  silicates.  147 

Portland  artificial  cements  128,  295 

"      cements,  strength  of   523,  557 

"      cement  of  Boulogne   87-95,498 

"      cement,  a  superior  article, 

517-519,  524 

"  "      tractile  strength  of  516 

"  *'      used  at  Cherbourg   521 

"  "      used  "  en  coulis"  515-517 

Portland  and  Roman  cement  mortars, 

compared   522-530 

Potash  and  soda,  how  detected. 

193-195,  216  -221 
"  "     in  hydr.  limestones, 

16,111,  193,  194 
"  "     in  mural  efflorescences..  569 

Potomac  River,  cement  works  on, 

15,  71-78,  268,  275 

Potsdam  sandstone,   6 

Pouilly,  cement  of   295 

Pozzuolana.102,  111,  112,152-154,156,  157,  295 

"        analysis  of   226 

"       artificial   150,  157 

"       Italian  in  sea  water, 

152, 153,  155,  157,  295 

with  fat  lime  558-5.59,  588-589 

"        Roman  mortar   555 

Precautions  in  selecting  cement  stones. .  170 

"       with  slaked  lime   321,323 

"       in  selecting  cement  for  test- 
ing    28,  29 

"       in  mixing    good  and   bad  • 

cements   44 

Preliminary  trials  of  cement  stones. .  172-182 

Prepaxation  of  lime  and  clay  cement   126 

"       for  qualitative  examination.  187 

Preservation  of  cements   298.  299 

"  "  limes   339-341 

Pricking  up   401 

Process  of  silici/ying   146-149 

Prominent  features  of  cement  stones..  46-95 

Properties  of  arenes    116 

"      '•  Bo ilogne  Portland  cement.  92 

"      "•  pozzuolanas    112 

"  trass   113 

Proportion  of  alkaline  silicate   145 

Proportion  of  ingredients,  St.  Leger  hyd. 

lime   133 

Proportion  of  ingredients  for  mortars  344 

Proportion  of  lime  and  clay  in  artificial 
cement   126 


Paraerapl*. 

Proportion  of  lime  for  cement  mortars.. . 

"  "  sand  to  gang  of  mortars^. . .  314 
"       "  clay  in  Portland  cement...  87 

Protecting  coat  for  sea  walls   160 

Proximity  to  sea  favors  efflorescence   570 

Psammites  Ill,  119 

Pure  cement  with  excess  of  water   509 

Pure  limestone   96 

Purest  calcareous  minerals   100 

Qualitative  examination   183-197 

Quantitative  examination   198-227 

Quarries  of  water  lime   20 

Quarry  of  hydraulic  lime,  Massachusetts,  22 

Quicklime,  how  produced.   96 

"      mixed  with  alkaline  silicates.  142 

Ravier's  report  on  cements  and  pozzuo- 
lanas. .   155-156 

Ramming  concrete  underwater  injurious  4fi9 

Ransome's  process-  for  hardening,  etc   600 

Remedies  for  efflorescence   571-577 

Remedy  for  feebly  hydraulic  limes,  etc. . .  145 

Rendering   401-403 

Report    by    M.    Delesse,  on  Boulogne 

Portland  cement  87-94 

Report  of  M.  Ravier,  on  seaworthy  ce- 
ments and  pozzuolanas   155,  156 

Restoration  of  detei-ioi-ated  cements.  301-304 
Revetting  concrete  walls  with  stone.  471^73 

Rhine,  trass  in  the  valley  of  the  113,  114 

Rockland  lump-lime   330 

Roman  cements  85.  86,  124,  226,  292,  294 

Roman  cement  mortars,  strens^th  of.  .,557-523 
Roman  and    Portland  cement  mortars 

compared   ,   .....  5-?2-530,  557 

Rondout  ground  lime   330 

Roofiny  concrete  for  arches    493 

Rosendale  cements  20,  26,  290 

Rosendale  Cement  Co.,  Lawrence  brand  62 

cements  contain  alkalies   591 

"        cement  mortars,  stren<;th  of, 

5:20,  557 

"         "      stone,  where  found,  21,  38 

"         "      layers  of   39 

"         "      injected  under  water, 

494-497 

Rosendale  and  Kingston  Cement  Co...  70 
"         "  mortars  .. .555,  .557 

Round  Top  cement  strength  of   557 

works,  Md., 

75,  76,  124,  226 

Rubble  masonry,  pointing  of   388 

Rupture,  instant  of   34 

Sand,  computation  of  voids  in  315 

"     used  in  testing   29 

"     in  Portland  cements   87 

"     not  necessary  for  hyd.  cement 

paste   109 

Sand,  proportion  of  in  mortars  314 

Sand  rock,  calcareous   7 

"      "   transition  of  Eaton    10 

"    sifting  the   316 

"   used  in  mortars   311,  313 

"   usually  added  to  pozzuolana   112 

Sandusky  cement  mortars   557 

"      works    81,  124 

"      limestone,  analysis  of   226 

Sand,  why  used  in  mortars   104 

Saponifying  salts  in  efflorescences. . .  574-577 

Scratch  coat  401,  404,  414,  415,  419-429 

Schists   111.  119 

Screed  coat  and  set  404,  407,  415,  416 

Sea-walls,  mortar  of,  how  protected  160 


INDEX. 


T^aragraph. 

Sea-water,  cements  able  to  resist   158 

**      "      pozzuolana  mortars  in   150 

"  "  its  effect  on  hydraulic  mortars  297 
"      "      its  effect  on  mortars  artiaci- 

ally  tested    435^38 

Sea-water;  European  limes  etc  in.  150-162,  435 

*'      "      lor  mixing  cement   495 

Section  of  Rosundale  cement  deposits   44 

Septaria,  for  Koinan  cement...  86,  87,  124,  512 

Setting  of  mortar  defined    120 

"     "  mortars,  action  of  magnesia 

on  the    590 

Setting  of  mortars  of  common  lime   5ol 

"     "  mortars  influenced  by  tempe- 
rature  124 

Shawangunk  conglomerate,   288 

Sheet  piles  in  founding  with  concrete  . . .  470 
Sliepherdstown  cement  contains  alkalies.  591 
"  "      mortars, strength  of  557 

"  "      works,  Va.,   72-74 

"  '•      limestone  226 

Sheppy  Roman  cem  ent   86 

Shrinking  does  not  occur  in  cements   109 

of  paste  of  fat  lime..   103 

Sifting  cements  for  testing   29 

"      sand  for  mortars . .    316 

Silica  in  hyd.  limestone   4 

how  detected   189,206,225 

"    in  poor  limes   106 

"    when  in  excess  in  cements   592 

Silicate  of  potash  or  of  soda   606, 607 

Silicatization  146-149 

"         definition  of  the  term   602 

Silicious  limestone,  products  of  burning.  584 

Sing-Sing  lump  lime,  slaking  of   330 

Slaking,  experiments  by  Gen.  Totten  on.  329 

"     hydraulic  limes   107 

by  immersion   323 

"     lime,  ordinary  method  of.   359-364 

effects  of   96,  104 

"     lime,  methods  of.   317-383 

"     poor  or  meagre  limes   105 

"     spontaneous  or  air   324-325 

Slaty  limestone   10 

Sling-cart  for  conveying  concrete   456 

Slipped  work   408,  409,  412 

Slow  setting  of  Portland  cements   93 

Smeaton's  opinion  of  trass   115 

Smith's  forge  scales  for  stucco  work   422 

Soda  and  potash,  how  detected, 

194, 195,  220,  221 

Soda  and  potash  in  hyd.  limestones   16 

"  in  efflorescences   569 

Soluble  glass,  in  mortars   551,  558 

"        '      with  bad  limestones        49,  141 

Solubility  of  lime  in  water   97 

Source  of  hydraulicity   182 

Spontaneous  slaking   324-325 

St.  Leger  hydraulic  lime   1.33 

Stone-breaking  machine   479-482 

"     cutters'  chips  for  concrete  477 

"     dyeing  608 

"     hardening   593,  607 

"     masonry,  mortar  for    380 

"  revetment  of  concrete  walls..  471-473 
Strength  of  mortars  injured  by  alkaline 

silicates    553 

Strength  of  aggregates   . .  312 

"•      "  certain  mortars   155 

"  concrete  experiments  on  the  498,  499 
"      of  mortars,  increase  of. . .  554-557 

Stucco  .389,  400,  408,  411,  414 

Subaqueous  works,  common  lime  in   104 

Subaqueous  work,  concrete  for   448 

Sugar  water  in  preparing  stucco    421 


Piira^raph. 

Sulphate  of  lime   148,  604 

"      "  magnesia  for  testing  effect  of 

sea  water   435-437 

Sulphate  of  soda  for  testing  lime   99 

Sulphide  of  hydrogen    195 

Sulphuric  acid,  how  detected   188,214 

"         "     a  solvent  for  pozzuolana.  112 

Temperature,  hydraulicity  influenced  by, 

123,  124 

Tennessee,  limestones  in    3 

Tentaculate  deposit   20,39 

Testing  mortars,  method  of   27-29 

"     wires  used  by  Gen.  Totten   121 

Test  for  limes  by  oxalic  acid   99 

general  character  of,  for  mortars..  30-32 

"   of  limestones  in  crucibles   46 

Theil,  hydraulic  lime    154,  156,  502 

"  "        "    mortar,  strength  of.  555 

"     lime,  analysis  of  2<;6 

Theoretical  minimum  of  cementing  sub- 
stances  314 

Theory  of  the  formation  of  laitance   475 

"        •'  hydraulic  induration   582-592 

"        "  the  hydi-anlicity  of  aienes   117 

"        "  mixing  cement  stones  and 

fuel  not  tenable  ,   236 

Theory  of  subaqueous  induration   117 

Thickness  of  Rosendale  cement  beds   39 

Three-coat  work   4 14  417 

Tools  required  in  plastering  and  pointing, 

387,  390-392 

Tostain's  opinion  of  pozzuolanas   15-3 

Totten's  (Gen.)  experiments  on  mortars  121 
"  slacking 

lime   3^8,  338-344 

Totten's  (Gen.)  trials  of  strength  of  con- 
cretes  499 

Toulon  Graving  Dock,  concrete  blocks 

for     .501 

Tractile  strength  of  Portland  and  Roman 

cements  521,  524,  527,  530 

Tractile  strength  of  pure  Portland  cement  516 

Transition  sandrock  of  Eaton   10 

Transverse  strain  of  mortars   30 

Trass,  analysis  of   226 

"    mortars  with  fat  lime   5.58-560 

"    or  Terras   102,  111,  113-115,  157 

"    where  found   113,114 

Treatment  in  burning  hydraulic  limes, &c.  234 
Treatment  required  for  intermediate  limes  180 

Tremie  for  laying  concrete  in  water   464 

Trenton  group  of  limestones   7,  11 

Treussart's  (Gen.)  experiments  with  mor- 
tars  .558,  559 

Treussart's  (Gen.)  objections  to  needle 

test   35,  36 

Trials,  preliminary,  of  cement  stones.  172-182 
Trying  sea-mortars  in  the  laboratory.. 435-437 

Try-kilns   ...  46 

Two-coat  work   404 

Ulster  Co.  deposits  of  cement, 

20, 21,  .38, 44,  226,  264,  268,  288 
"      layers  of  intermediate  lime  in, 

110,  300 

Underburnt  cement  stones   177,2^2 

"        limestones  for  artificial  puz- 

zuolanas   136,  187 

United  States,  common  lini«  in   1 

"  argillaceous  and  argillo- 

magnesian  limestones  in. .5,  12 

"  calcareous  deposits  in   167 

"  deposits  of  hyd.  limes  in . .  11)8 
"  intermediate  limes  in   110 


334 


INDEX. 


Paragraph, 

United  States,  puzzuolanas  not  known  to 
exist  in   112 

Utica  cement,  strength  of   557 

"       "      works,  111   80,  124 

"   limestone,  analysis  of    226 

"   slate   12 

Vaillant  (Marshal)  on  hydraulic  materials  151 
"           "       report  on  raaj^nesian 
hydrates   590 

Variations  of  temperature,  influence  set- 
ting  123,  124 

Variety  of  cement  stones  requires  variety 
of  treatment   234 

Vassy,  cement  of   294,  295 

Vicat's  dividing  limes  ,   43,  110 

"     and  Keibell's  experiments...  510-518 
"      mode  of  trying  sea-mortars  in 
laboratory  435-437 

Vicat  on  natural  Boulogne  Portland  ce- 
ment   95 

Vicat's  opinion  of  artificial  hydraulic 
limes   127 

Vicat's  opinions  on  the  needle-test   35 


"  "     "  slaking   o20 

"    researches  on  the  cftects  of  sea- 
water  159-1()1,  295,  29(» 

Virginia  and  Pennsylvania  beds  of  com- 
pound limestones  3,  15 

Vitruvius  speaks  of  pozznolana   112 

Volcanic  origin  of  pozzuolana    112 

Water  absorbed  by  the  Boulogne  ce- 
ments     92 

Water,  intermediate  limes  under   110 

arenes  under   116 

"     laying  concrete  in  464,466-468,  475 

hardening  of  limes  in  102-107 

"     hydraulic  cements  under  109 

"     laying  concrete  under  464-475 

Water-limestone   20 

Western  cements,  where  made   24 

West  Point,  efflorescence  from   567 

West  Springfield,  Mass.,  limestones    22 

Wheelbarrows  for  conveying  concrete   454 

Whitewashing,  lime  for   321 

Wire  test  of  pure  cement   122 

"       by  General  Totten   121 


INDEX  TO  APPENDIX. 


Page.  I 

Analysis  of  cost  of  concrete   322-325 

Comparison  of  Portland  and  Eosendale 

concrete   325 

Concrete  mixer   325,326 

Composition  of  various  concretes. . .  322-324 

Gravel  for  concrete     319 

Mill-made  concrete   320 

Mortar,  volumes  of.   321,  322 


Page. 

Mixtures  of  broken  stone  and  gravel  319,  320 

Portland  cement   317 

Eosendale  cement   319 

Standard  qualities  of  cements   318,319 

Stone  for  concrete   319 

Strength  of  concrete  mortars   321-325 

Voids  in  mixtures  of  stone  and  gravel . . .  320 
Volumes  of  cement  paste   321,  322 


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D.  VAN  NOSTRAND'S  CATALOGUE. 


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GRUNER,  M.  L— The  Manufacture  of  Steel. 

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10 


D.  TAN  NOSTRAND'S  CATALOGUE. 


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HOLLEY,  ALEXANDER  L— A  Treatise  on  Ordnance  and  Armor. 

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JANNETTAZ,  EDWARD.— A  Guide  to  the  Determination  of 
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12 


D.  VAN  NOSTRAND'S  CATALOGUE. 


KING,  W.  H— Lessons  and  Practical  Notes  on  Steam, 

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D.  VAN  NOSTRAND'S  CATALOGUE. 


MINIFIE,  WM— Mechanical  Drawing. 

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